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preface

This dictionary is published by the Bureau of Mines as a contribution to the mining and mineral literature in the be- lief that it will fill a recognized need.

Several attempts have been made over the years to revise Albert Fay’s Glossary of the Mining and Mineral Industry which first appeared in December of 1918. Frank L. Hess of the Bureau of Mines worked on a revision, but his un- timely death prevented its completion. Subsequently, the writer was employed to compile and edit this dictionary in cooperation with the technical staff of the Bureau of Mines.

Fay’s glossary contained about 18,000 terms with 27,000 definitions; the pres- ent compilation contains about 55,000 terms with approximately 150,000 def- initions. These terms are of both a tech- nical and local nature, and they apply to metal mining, coal mining, quarrying, geology, metallurgy, ceramics and clays, glassmaking, minerals and mineralogy, and general terminology. Petroleum, natural gas, and legal mining terminol- ogy, unless of a general nature, has been excluded, as has been foreign terminol- ogy where there is an English equivalent. Several thousand Spanish-American mining terms that appeared in Fay’s compilation have been removed to make way for the thousands of new English terms that have evolved over the years. Those Spanish-American and Mexican terms still used in the Southwestern United States have been retained.

Fay’s compilation included terminol- ogy from the entire English-speaking world. This objective has been main- tained in this dictionary. Many terms are identified by the country or area of ori-

gin. Others can be identified by examin- ing the source following each definition. These sources are completely identified, with full bibliographical information, in the list of authorities and sources in the back of the dictionary. A consultation of this list can also aid in establishing the recency of the definition. Several thou- sand terms from Fay that might be con- sidered obsolete were retained because it was felt that we had an obligation to preserve the historical record.

The list of authorities and sources in the back of the dictionary is only a par- tial listing of the sources consulted in compiling this dictionary. The items in this list are for the most part dictionaries, glossaries, or other tools that were found to be fruitful sources of information. Abbreviations of sources and references and other symbols used in the dictionary are identified in alphabetical sequence in the list of authorities and sources. Many additional citations from text- books, research reports, and periodicals are given individually throughout the body of the dictionary following each definition. Geographical abbreviations are also listed in the back of the dic- tionary.

It is too much to hope that the first edition of a volume such as this will be free from error. The Bureau of Mines will appreciate having errors pointed out, and will welcome suggestions for the inclusion of additional terms that may appear to be desirable. Communi- cations should be addressed to the Office of Mineral Information, Bureau of Mines, U.S. Department of the Interior, Washington, D.C. 20240.

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acknowledgments

In the compilation of this dictionary, the Bureau of Mines gives credit for each definition as indicated in the list of authorities and sources quoted. Def- initions credited Webster 3d in the text have been reproduced by special per- mission from Webster’s Third New In- ternational Dictionary, copyright 1966 by the G. & C. Merriam Co., publishers of the Merriam-Webster Dictionaries. Reprinting of these definitions herein in truncated form is not to affect in any way the validity of the proprietary rights of the G. & C. Merriam Co. to the re- printed definitions. Definitions credited Webster 2d in the text have been re- produced by special permission from Webster’s New International Dictionary, Second Edition, copyright 1959 by G. & C. Merriam Co., publishers of the Merriam-Webster Dictionaries, and their reprinting herein in truncated form is not to affect in any way the validity of the proprietary right of G. & C. Merriam Co. to the reprinted definitions. Material quoted from Webster’s 2d Edition is of historical im- portance or is material not retained in Webster’s 3d Edition.

In all, several hundred specialists of the Bureau of Mines read various sec- tions of this dictionary for technical re- view. No section was read by fewer than two specialists. Since a listing of in- dividual names would be extensive, grateful acknowledgment is here made for their efforts and for the suggestions and changes recommended by them. James E. Hill and Dr. C. Meade Patter- son reviewed the mineral list; Taber de Polo and the late Howard P. Hamlin re- viewed the ceramics list; and Dr. Pat- terson reviewed the general list and part of the geology list, and compiled a list of single-letter abbreviations that has been incorporated in the dictionary. Other Bureau personnel whose services deserve special acknowledgment include Earle P. Shoub, who reactivated the project

after Hess’ death; A. L. Julian, Jr., whose enthusiastic support reinforced my efforts over the past 6 years; Carl Rampacek and Robert P. Willing, both of whom gave valuable assistance and administrative counsel; Hazel J. Strat- ton, who gave valuable advice on edi- torial style; and Marion Hatch, whose unexcelled proficiency in library services helped to make the task easier. Special acknowledgment is due Charles W. Mer- rill, whose continuing interest and pro- fessional counsel played a major role in insuring the final completion of the proj- ect. In the final phase of the project, Dr. Miles J. Martin of Washington and Meyer Reiness of Pittsburgh provided the administrative authority and guid- ance needed to bring this long-standing project to a conclusion.

Finally, several people outside the Bureau deserve recognition for their help. I am indebted to Mr. Daniel R. Pfoutz, Head of the Science and Tech- nology Department of Carnegie Library of Pittsburgh, Pa., who relaxed the rules and permitted me to use many noncir- culating reference tools outside the lib- rary for this project; and to Mrs. Vir- ginia R. Fischel, retired professor of library science at the Carnegie Institute of Technology, whose suggestions of sources led to the inclusion of several thousand terms in this compilation.

The contributions of three persons deserve special recognition. Mrs. David Mischelevich, formerly with the Bureau of Mines and now with the U.S. Geolog- ical Survey, made many significant con- tributions in the early stages of this project. To Marilyn Pantone and Pau- line Mekon I owe my deepest gratitude and enduring regard for their coopera- tion and superior performance. Both of them started with me in 1961 and have remained loyal and dedicated through many vicissitudes. Without their in- valuable assistance, this seemingly end- less task could not have been completed.

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a a. Abbreviation for atom; atomic. Webster 3d. b. Symbol for surface per unit volume. Zimmerman, p. 104. c. Abbreviation for acre. Also abbreviated A. Zimmerman, p. 3; Handbook of Chemistry and Physics, 45th ed., 1964, p. F-97. d. Abbreviation for are (land area). Zimmerman, p. 11. e. Abbreviation for air. Webster 3d. £. Symbol for one of the three crystallographic axes a, b, c. Each axis is designated the a axis in the isometric crystal system in which all three axes are equal. Also given as a. Bu- reau of Mines Staff. g. Abbreviation for acceleration and the symbol for linear ac- celeration. Handbook of Chemistry and Physics, 45th ed., 1964, p. F-98; Webster 3d. h. Abbreviation for aqua. Webster 3d. i. Abbreviation for anterior. Webster 3d. j. Abbreviation for asymmetric. Webster 3d, k. Symbol in structural petrology for the direction of tectonic transport, similar to the direction in which cards might slide over one another. Striations in a slicken- sided surface are parallel to direction a. A.G.I., p. 1. 1. As a subscript, the symbol for adsorbed. Zimmerman, p. 168. m. Ab- breviation for activity. Zimmerman, p. 4. n. Symbol for major axis of an ellipse or of an ellipsoid. Zimmerman, p. 13. 0. Sym- bol for the standard temperature gradient of the atmosphere. Zimmerman, p. 106. p. Symbol for the characteristic of barometric tendency or of a barograph trace, during the past 3 hours. Zimmerman, pp. 428, 439,

aa. Symbol for surface per unit volume. Zimmerman, p. 146. b. Symbol for activity ; chemical activity. Zimmerman, pp. 145, 150. c. Symbol for acceleration. Zimmer- man, p. 148. d. Symbol for the velocity of sound, Zimmerman, p. 368. e. With sub- script O, as do, the symbol for one of the unit-cell parameters, do, bo, co. Bureau of Mines Staff. f. As a subscript, the symbol for adsorbed. Handbook of Chemistry and Physics, 45th ed., 1964, p. F-98. g. With subscript 1, as a:, the symbol for. the Bohr radius. Zimmerman, p. 163. h. Symbol for aperture; slit width. Zimmerman, pp. 148, 165. i. Symbol for the coefficient of ac- commodation. Zimmerman, 1. 152. j. Sym- bol for standard temperature gradient of the atmosphere. Zimmerman, p. 426.

a-; am-. Prefix indicating absence, for exam- ple, amorphous (without crystalline form) ; anhydrous (not containing water). Pryor. 3.

a-(direction). In structural petrology, the di- rection of tectonic transport, similar to the direction in which cards might slide over one another. Striae in a slickensided sur- face are parallel to a. A.G.I.

A a. Abbreviation for angstrom; angstrom unit. Also abbreviated a; A. BuMin Style Guide, p. 58; Webster 3d; Zimmerman, pf. 10, b. Abbreviation for absolute tem- perature. Zimmerman, p. 3. c. Formerly the chemical symbol for argon, but Ar, has replaced it. CCD. 6d, 1961. d. Symbol for mass number. Webster 3d. e. Abbreviation for area; cross-sectional area; surface area. Zimmerman, pp. 11, 32, 104. £. Abbrevia- tion for air. Also abbreviated a. Zimmer- man, p. 5; Webster 3d. g. Abbreviation for asbestos. Zimmerman, p. 214. h. Abbrevia- tion for ampere. Webster 3d. i. Abbrevia- tion for amplitude. Zimmerman, p. 8. j. Abbreviation for anode. Also abbreviated a. Zimmerman, p. 10. k. Abbreviation for Arctic. Zimmerman, p. 6. 1. Abbreviation for arroyo. Zimmerman, p. 11. m. Abbre- viation for arch. Zimmerman, p. 11. an. Abbreviation for aperture. Also abbrevi- ated a. Zimmerman, p. 10. 0. Symbol for hail. Zimmerman, p. 52. p. Symbol for attenuation constant in acoustics. Zimmer- man, p. 13. q. Symbol for magnetic vector potential. Zimmerman, p. 162.

A a. Symbol for atomic weight. Zimmerman, pf. 151. b. Symbol for area; surface area; Cross-sectional area; total cross-sectional area. Zimmerman, pp. 151, 170, 185, 365. c. Abbreviation for amplitude. Zimmer- man, p. 150. d. Abbreviation for aperture. Zimmerman, p. 148. e. Symbol for the re- fracting angle of a prism. Handbook of Chemistry and Physics, 45th ed., 1964, p. F-98. f. Symbol for power gain of ampli- fier; power amplification of amplifier; volt- age gain of amplifier; voltage amplification of amplifier; amplification of amplifier voltage. Handbook of Chemistry and Phys- ics, 45th ed., 1964, p. F-98; Zimmerman, pp. 150, 156. g. Symbol for attenuation constant in sound transmission. Zimmer- man, p. 189. h. Symbol for sheet current density. Zimmerman, p. 260.

aa Abbreviation for acetic acid. Handbook of Chemistry and Physics, 45th ed., 1964, p. C-74,

aa (pronounced ah-ah). A Hawaiian term for lava consisting of a rough assemblage of clinkerlike scoriaceous masses. It is con- trasted with pahoehoe used to designate the smoother flows. Fay; Hess.

Aalenian. Lowermost Middle or uppermost Lower Jurassic. A.G.I. Supp.

A-alloy. An alloy containing 3 per cent cop- per, 20 percent zinc, and 77 percent alu- minum; developed by the Alloys Research Committee of the British Institution of Mechanical Engineers; very susceptible to

A-alloy

corrosion. Chem. & Met. Eng., v. 26, April 12, 1922, p. 690.

AAPG Abbreviation for the American Asso- ciation of Petroleum Geologists. Williams.

Aasby diabase. An olivine diabase contain- ing biotite, ilmenite, and apatite in addi- tion to labradorite, augite, and olivine; from Aasby, Sweden. Holmes, 1928.

AASHO (American Association of State Highway Officials) compaction. See com- paction test. ASCE P1826.

a-axis. In structural petrology, the direction of movement or transport in a tectonite. This may be parallel to lineation, as in many shear zones (slickensides), or normal thereto, as in regionally folded metamor- phic terranes. A.G.I.

ab- A prefix added to the names of the practical electrical units to indicate the corresponding unit in the cgs (centimeter- gram-second) electromagnetic system, or the electromagnetic unit (emu) ; for exam- ple, abampere; abcoulomb; abvolt. Hand- book of Chemistry and Physics, 45th ed., 1964, p. F-29.

abalone. The mollusc Haliotis, also known as an ormer or ear shell. From the Pacific waters of California; Mexico; Japan; and New Zealand. See also Haliotis. Shipley.

abalone pearl. A colored pearl from the aba- lone. Usually a blister pearl although a true pearl is found occasionally, especially in Mexico and in California. Usually of pronounced green, pale green, or pink hues. Shipley.

abamp. Abbreviation for absolute ampere. BuMin Style Guide, p. 58.

abampere. The centimeter-gram-second -(cgs) electromagnetic unit of current, that is, that current which, in a one-turn circular conductor of 1 centimeter radius in a vac- uum, produces a magnetic intensity of 27 oersteds at the center of the circuit. Equals 10 absolute amperes. Hess.

abandon. To stop drilling and remove the drill rig from the site of a borehole before the intended depth or target is reached. Long.

abandoned cliff; ancient cliff. Cliff abandoned by the sea in consequence of negative movements of the sea level. Schieferdecker.

abandoned mine. See abandoned workings.

abandoned well. An oil or gas well aban- doned because its yield has fallen below that necessary for profitable production. A.G.I, Supp.

abandoned workings. Excavations, either caved or sealed, that are deserted and in which further mining is not intended and opening workings which are not ventilated and inspected regularly. U.S. BuMines Federal Mine Safety Code—Bituminous Coal and Lignite Mines, Pt. I Under- ground Mines, October 8, 1953.

abandonment. The act of abandoning; relin- quishment. Webster 3d. Abandonment of a mining claim may be by failure to per- form work, by conveyance, by absence, and by lapse of time. The abandonment of a mining claim is a question of intent. To constitute an abandonment of a mining claim, there must be a going away, and a relinquishment of rights, with the intention never to return, and with a voluntary and independent purpose to surrender the loca- tion or claim to the next comer. Compare forfeiture. Fay.

abandonment plans. Gr. Brit. The plans, drawings, and sections required by law to be sent to the District Inspector of Mines, following the abandonment of a seam or

mine. B.S. 3618, 1963, sec. 1.

abas. The Persian weight for pearls, about 2.66 troy grains. Shipley.

abate. In metalworking, to lower the temper of. Standard, 1964.

abatis; abattis. Leic. Walls or ranges ot rough wood, for example, cordwood placed crossways to keep the underground roads open for ventilation, etc. Fay.

Abbcite. Ammonia dynamite containing a high percentage of alkali chloride. Used as an explosive in coal mining. Bennett 2d, 1962.

Abbe jar. In mineral processing, a porcelain jar used for laboratory batch grinding tests in ceramic ware. Pryor, Cc.

Abbe number; Abbe value. A measure of the optical dispersion of a glass. Dodd.

Abbe theory. The visibility of an object under the microscope is directly propor- tional to the wavelength of light, and in- versely as aperture of lens. Pryor, 3.

Abbe tube mill. A gear-driven tube mill sup- ported on a pair of riding rings and distinguished by an Archimedes spiral, through which the ore is fed and dis- charged. Grinding is effected by flint peb- bles fed into the mill. See also ball mill. Liddell 2d, p. 355.

Abbe value. See Abbe number. Dodd.

A.B.C. Process of Sewage Disposal. Precipi- tation of sewage sludge by the use of alum, blood, charcoal, and clay. Ham.

ABC system. A method of seismic surveying by which the effect of irregular weathering thickness may be determined by a simple calculation from reciprocal placement of shotholes and seismometers. The method was originally used to solve refraction prob- lems arising from irregularities in the top of the high-velocity layer. A.G.I.

Abegg rule. Maximum positive valence plus maximum negative valence usually totals 8, notably with 4th, 5th, 6th, and 7th group elements. Pryor, 3.

Abel flashpoint apparatus. Used for deter- mining the flashpoint of petroleum. Bennett 2d, 1962 Add.

Abel heat test. A test used to assess the chemical stability of an explosive, and this test can also be used to determine the degree of deterioration that may have oc- curred during long periods of storage. McAdam II, p. 21.

Abelite. Ammonium nitrate and _ trinitroto- luene composition used as an explosive. Bennett 2d, 1962.

Abel’s reagent. Etching agent consisting of 10 percent chromium trioxide in water. Used in the analysis of carbon steels. Bennett 2d, 1962.

abernathyite. A rare, yellow secondary min- eral, K(UO2z) AsO.4H2O, of the meta- autunite group; a potassium analogue of uranospinite, containing 52.8 percent ura- nium; tetragonal. Small yellow crystals from the Temple Mountains, Utah. Fron- del, p. 175; Spencer 21, M.M., 1958.

aberration. The failure of a lens or mirror to bring the light rays to the same focus. When aberration is due to the form of the lens or mirror it is called spherical aberra- tion. When due to the different refrangi- bility of light of different colors, it is called chromatic aberration. When present in magnifiers it often causes inaccurate de- cisions as to flawlessness or color of gems. Shipley.

Aberson machine. Dodd.

abime. A large, steep-sided vertical shaft

See soft-mud process.

abraser

opening at the surface of the ground. A.G.I.

abioglyph. A marking (hieroglyph) of inor- ganic origin. Pettijohn.

A bit. A nonstandard, obsolete size diamond- drill bit. Long.

ablation. a. The formation of residual de- posits by the washing away of loose or soluble minerals. Fay. b. The wearing away of rocks, or surface melting of gla- ciers. Standard, 1964. c. The combined processes that decrease the size of a gla- cier. Mather.

ablation area. That part of a glacier or snow- field where ablation exceeds accumulation. Also called area of dissipation; dissipator. A.G.I.

ablatograph. An instrument that records ablation by measuring the distance which a snow or ice surface sinks during the period of observation. A.G.I.

A.B. Meco-Moore. An improved form of Meco-Moore—the pioneer of cutter loaders in Great Britain. A bulky machine which cuts a deep web of coal up to 6 feet and used in cyclic mining in medium to thick seams. It runs on the floor of the seam and does not require a prop-free front. It car- ries two horizontal jibs, one cutting at floor level and the other at a height depending on seam conditions. The use of the Meco- Moore is declining. Nelson.

Abney level. A surveying instrument for taking levels up steep slopes; also used as a clinometer. Ham.

abnormal. Deviating from the normal; dif- fering from the typical; irregular; unusual. Webster 3d,

abnormal place. A working place in a coal mine with adverse geological or other con- ditions and in which the miner is unable to earn a wage, based on the pricelist, equal to or above the minimum wage. A term generally associated with stalls or pillar methods of working. Nelson.

Aboglas. Sheeting of asbestos and glass fibers. Used as an insulator. Bennett 2d, 1962 Add.

ab-plane. In structural petrology, the surface along which differential movement takes place. A is the direction of displacement —that is, the direction of tectonic trans- port; b lies in this surface of movement and is perpendicular to a. A.G.I.

abradant. An abrading substance, as emery, sand, etc., used in grinding, polishing, etc. Standard, 1964. See also abrasive. Fay.

abrade. a. To rub or wear off; to waste or wear away by friction, as to abrade rocks. Webster 3d. b. As used in the sharpening- stone industry, abrading means cutting, as the steel composing the tool is cut away rather than worn away. Fay. c. The wear- ing away of diamonds, drill-bit matrices, and drill-stem equipment by frictional con- tact with the rock material penetrated or by contact with the cuttings produced by the action of the drill bit in drilling a borehole. Long.

abrading. Wearing away any substance with an abrasive. Mersereau, 4th, p. 285.

Abram’s law. Strength of concrete depends on water-to-cement ratio of mixture. Mini- mum needed for chemical action is 0.35 to 1. Pryor, 3.

abraser. A device for assessing the wear re- sistance of surfaces. The specimen to be tested is rubbed alternately by the flat faces of two weighted abrasive wheels. These wheels revolve in opposite directions through frictional contact with the speci-

abraser

men and exert a combined abrasive, com- pressive, and twisting action twice in each revolution of the specimen holder. Osborne.

abrasion. a. The wearing away by friction. A.G.I. b. The act of wearing or rubbing off. A.G.I. c. Wearing away by rubbing or friction, the chief agents being currents of water laden with sand and other rock de- bris and by glaciers. A.G.I. d. The opera- tion of wearing away by aqueous or glacial action. A.G.J.

abrasion hardness. Hardness expressed in quantitative terms or numbers indicating the degree to which a substance resists being worn away by frictional contact with an abrasive material, such as silica or car- borundum grits. Also called abrasion re- sistance; wear resistance. Compare scratch hardness. Long.

abrasion index. The percentage of a specially prepared 3 in.—2 in. sample of coke re- maining on a %-inch mesh B.S. test sieve after the sample of coke has been sub- jected to a standardized abrasion proce- dure in a rotating drum. B.S. 1016, 1961, Piel 6:

abrasion of refractories. Wearing away of the surfaces of refractory bodies in service by the abrading action of moving solids. HW.

abrasion platform. An uplifted abrasion plat- form of large areal extent is a marine peneplain or a marine plane, according to the smoothness of the surface produced by wave erosion. A.G_I.

abrasion resistance. The degree to which a porcelain enamel will resist attack by abra- sive materials. ASTM C286-65. See also abrasion hardness.

abrasion shoreline. See shoreline of retrogra- dation. Schieferdecker.

abrasive. A substance used for grinding, honing, lapping, superfinishing, polishing, pressure blasting, or barrel finishing. It includes natural materials such as garnet, emery, corundum, and diamond, and elec- tric-furnace products like aluminum oxide, silicon carbide, and boron carbide. ASM Gloss. Natural abrasives in order of hard- ness include diamond, corundum, emery, garnet, and pumice. Artificial abrasives in- clude borazon, carborundum, corundum (sold as alundum, aloxite, etc.), boron carbide. For preparing polished surfaces on mineral specimens, carborundum, levi- gated alumina, jeweler’s rouge, and mag- nesia are much used, diamond-impreg- nated paste being employed at final stage. Pryor, 3.

abrasive belt. A coated abrasive product, in the form of a belt, used in production grinding and polishing. ASM Gloss.

abrasive disk. a. A grinding wheel which is mounted on a steel plate, with the exposed flat side being used for grinding. ASM Gloss. b. A disk-shaped, coated abrasive product. ASM Gloss.

abrasive drilling. A rotary drilling method in which drilling is effected by the abrasive action of the drill steel or drilling medium which rotates while being pressed against the rock. Fraenkel, v. 1, Art. 8:30, p. 21.

abrasive finishing. The final cuts taken with a grinding wheel to obtain the accuracy and surface desired. ACSG, 1963.

abrasive formation. A rock consisting of small, hard, sharp-cornered, angular frag- ments, or a rock, the cuttings from which, produced by the action of a drill bit, are hard, sharp-cornered, angular grains, which grind away or abrade the metal on bits and drill-stem equipment at a rapid rate.

Also called abrasive ground. Long.

abrasive ground. Synonym for abrasive for- mation. Long.

abrasive hardness test. This test employs a rotating abrasive wheel or plate against which specimens are held. The specimens are abraded for a given number of revo- lutions and the weight of material lost is a measure of the abrasive hardness. Lewis, p. 574.

abrasive tumbling. See ACSG, 1963.

abraum salts. See abraumsalze.

abraumsalze; abraum salts. Ger. Mixed sulfates and chlorides of potassium, so- dium, and magnesium overlying the rock salt in the Stassfurt salt deposits. Holmes, 1928.

abriachanite. An earthy, amorphous form of crocidolite. Dana 6d, p. 400.

abros. A _ stainless and corrosion-resisting alloy containing 10 percent chromium, 88 percent nickel, and 2 percent manganese. Campbell.

abs Abbreviation for absolute. BuMin Style Guide, p. 58.

absarokite. An alkalic basalt consisting of about equal amounts of olivine, augite, labradorite, and sanidine, with accessory biotite, apatite, and opaque oxides. Leucite is sometimes present in small amounts. Absarokite forms a series with shoshonite with decreasing amounts of olivine and increasing amounts of plagioclase and sanidine. A.G_I.

abscissa. The axis at right angles to the axis of ordinates. Crispin.

absolute. a. In chemistry, free from impurity or admixture. Hess. b. In physics, not de- pendent on any arbitrary standard. Hess. c. Frequently used in the trades to indi- cate a thing as being perfect or exact. Abbreviation, abs. Crispin.

absolute ampere. a. The current which, when flowing in a circular conductor of 1 centi- meter radius, produces at the center a field strength of 2x gauss. The ampere normally used in electrical engineering is one-tenth of this quantity. C.T.D. b. One- tenth of an abampere. Hess.

absolute atmosphere. An absolute unit of pressure equal to 1 million times the pres- sure produced on 1 square centimeter by the force of 1 dyne. Fay.

absolute chronology. The geologic chronol- ogy expressed in years. Schieferdecker.

absolute daily range. During the 24 hours of the day the difference between the maxi- mum easterly and maximum westerly values of the magnetic declination at any point. Mason, v. 2, p. 719.

absolute drought. In Great Britain, a mini- mum period of 15 consecutive days during which not more than 0.01 inch of rain has fallen; this definition is not accepted inter- nationally. Ham.

absolute humidity; humidity of air. The number of grams of water vapor per cubic meter of the air. From the mine ventila- tion aspect, the relative humidity is the important factor. See also saturated air. Nelson.

absolute isohypse. A line that has the prop- erties of both constant pressure and con- stant height above mean sea level. There- fore, it can be any contour line on a constant-pressure chart, or any isobar on a constant-height chart. H&G.

absolute ownership. In law, an unqualified title to property and the unquestioned right to immediate and unconditional pos-

barrel finishing.

absorber

session thereof. Standard, 1964. Applies to mining claims and properties. Hess.

absolute permeability. A measure of possible flow of a standard liquid under fixed con- ditions through a porous medium when there is no reaction between the liquid and the solids. This measure is arbitrarily taken for isothermal viscous flow. It can be duplicated with gases if tests are so conducted that extrapolation to infinite pressure can be made; specific permeabil- ity. Hess.

absolute potential. True potential difference between a metal and the solution in which it is immersed. Pryor, 3.

absolute pressure. a. Total pressure at a point in a fluid equaling the sum of the gage pressure and the atmospheric pres- sure. Webster 3d. b. Pressure measured with respect to O pressure, in units of force per unit of area. C.T.D.

absolute roof. a. The entire mass of strata overlying a coal seam. See also nether roof, a. Nelson. b. In mine subsidence, the entire mass of superjacent rocks. Briggs, p. 61. c. The entire mass of strata over- lying a subsurface point of reference. Bu- reau of Mines Staff.

absolute scale. See Kelvin temperature scale.

absolute temperature. Temperature reckoned from the absolute zero. Handbook of Chemistry and Physics, 45th ed., 1964, p. F-29,

absolute time. Geologic time measured in terms of years. Compare relative time. Leet.

absolute valency. The valence numerically equal to the number of electrons of an atom engaged in attaching other atoms. Pryor, 3.

absolute viscosity. The force required to move a plane surface of area 1 square centimeter over another parallel plane sur- face 1 centimeter away at a rate of 1 centimeter per second when both surfaces are immersed in the fluid. This force (the unit of absolute viscosity) is called the poise. Francis, 1965, v. 1, p. 210.

absolute zero. The temperature at which a gas would show no pressure if the general law for gases would hold for all tempera- tures. It is equal to —273.16°C or —459.69° F. Handbook of Chemistry and Physics, 45th ed., 1964, p. F-29.

absorb. To drink in or to suck up as a liquid by a solid like a sponge or fuller’s earth. Fay.

absorbed dose. Usually expressed as rads, which represents the energy absorbed from the radiation per gram of specified body tissue. BuMines Bull. 630, 1965, p. 747.

absorbed water. Water held mechanically in a soil mass and having physical properties not substantially different from ordinary water at the same temperature and pres- sure. ASCE P1826.

absorbent. A substance that absorbs. Crispin.

absorbent formation. A rock or rock material, which, by virtue of its dryness, porosity, or permeability, has the ability to drink in or suck up a drilling liquid, as a sponge absorbs water. Also called absorbent ground. Long.

absorbent ground. Synonym for absorbent formation. Long.

absorbents. Substances, such as wood meal and wheat flour, which are also ‘forms of low explosive when mixed with metallic nitrates, and tend to reduce the blasting power of the explosives making them suit- able for coal blasting. Cooper, pp. 345-346.

absorber. a. An apparatus in which gases are

absorber

brought into intimate contact with an ex- tended surface of an absorbing fluid so that they enter rapidly into solution. Ab- sorbers are used in saving casinghead gas- oline. Hess. b. The resistance and con- denser in series which is placed across a break in an electrical circuit in order to damp any possible oscillatory circuit, which would tend to maintain an arc or spark when a current is interrupted. Also called a spark absorber. C.T.D. c. Any material that absorbs or stops ionizing radiation. Strong neutron absorbers like boron, haf- nium, and cadmium are used in control rods. Lead, concrete, and steel attenuate gamma rays and neutrons in nuclear re- actor shields. A thin sheet of paper or metal will stop or absorb alpha particles and all but very energetic beta particles. See also poison. L@L.

absorber plant. A plant that has the ability to take on the characteristics of some elements in its cycle of life (for example, pifion tree absorption of a radioactive sub- stance and the consequent radioactivity released by some pinon trees). Ballard.

absorbing well. A well sunk for the purpose of draining away water. Ham. Absorbite. Trade name for activated char-

coal. Hess.

absorptiometer. A device for measuring the

solubility of a gas in a liquid. Bennett 2d, 1962.

absorptiometry. Measurement of the loss

through absorption by homogeneously col- ored solution of monochromatic light. Ab- sorption (Beer’s Law) is proportional to the number of molecules through which the light passes. The Bougner-Beer Law is L=To' <ylO mest

Where I is intensity; 1 is distance trav- eled; I, is original intensity; k is an ex- tinction coefficient; c is concentration (grams per liter). Measuring instruments are called absorptiometers or spectropho- tometers; much used types being the Lu- metron and the Spekker. The method is used where light (including ultraviolet) can be employed as an analytical colori- metric medium. It is much used in mineral dressing control analysis and _ research. Pryor, 3.

absorption. a. Taking up, assimilation, or in- corporation; as, the absorption of gases in liquids, as distinguished from adsorption. Sometimes loosely used in place of adsorp- tion. A.G.I, b. The act or process of ab- sorbing, imbibing, swallowing, or engulfing mechanically. Fay. c. A taking in or recep- tion by molecular or chemical action. Fay. d. The phenomenon observed when a pleo- chroic mineral is rotated in plane polarized light. In certain positions, the mineral is darker than in others, owing to the absorp- tion of light. Fay. e. In hydrology, a term applied to the entrance of surface water into the lithosphere by all methods. A.G.J. f. As applied to ceramic products, the weight of water which can be absorbed by the ware, expressed as a percentage of the weight of the dry ware. HW. g. The proc- ess by which a liquid is drawn into and tends to fill permeable pores in a porous solid body; also, the increase in weight of a porous solid body resulting from the penetration of a liquid into its permeable pores. ASTM C125-66.

absorption hygrometer. A type of hygrometer with which the water vapor content of the atmosphere is measured by means of the absorption of vapor by a_ hygroscopic

chemical. The amount of vapor absorbed may be determined in an absolute manner by weighing the hygroscopic material, or in a nonabsolute manner by measuring a physical property of the substance that varies with the amount of water vapor absorbed. The lithium chloride humidity strip and carbon-film hygrometer element are examples of the latter. H&G.

absorption loss. a. The loss of water occur-

ring during initial filling of a reservoir in wetting rocks and soil. Ham. b. That part of the transmission loss which is due to dissipation or the conversion of sound energy into some other form of energy, usually heat. This conversion may take place within the medium itself or upon a reflection at one of its boundaries. This loss is a critical factor in the effectiveness of sonar equipment. Hy.

absorption of gases. The solution of gases in

liquids or the absorption of gases by solids. In mining, the entry of oxygen into coal or carbonaceous matter may initiate slow combustion and fires when the conditions are favorable. See also spontaneous com- bustion. Nelson.

absorption oil. Oil containing little or no

gasoline, for example, mineral seal oil, used in the absorption process for extract- ing gasoline from natural gas. Bennett 2d, 1962.

absorption plant. Plant for recovering gaso-

line from natural gas by absorption. Ben- nett 2d, 1962,

absorption process. A method of treating wet

gas by passing it through an absorber in which large surfaces of mineral seal oil or a similar oil are exposed and absorb the heaviest fraction of the gas. This is later distilled from the oil and is known as casing-head gasoline. The oil is recircu- lated and the gasoline is piped to a con- denser and then to an accumulator. Hess.

absorption rate. a. The rate, expressed in

quantitative terms, at which a liquid, such as a drilling circulation medium, is absorbed by the rocks, or rock materials, penetrated by the dril] bit. Long. b. The amount of water absorbed when the brick is partially immersed for 1 minute; usually expressed either in grams or ounces per minute. Also called suction rate; initial rate of absorp-

tion. ACSG.

absorption ratio. See saturation coefficient.

Dodd.

absorption refrigeration. A process whereby

a secondary fluid absorbs the refrigerant, and in doing so, gives up heat, then re- leases the refrigerant, during which it ab- sorbs heat. Strock, 10.

absorption spectrum. The series of dark

bands crossing a continuous spectrum, seen when white light has been transmitted through a colored vapor, liquid, or solid. Anderson, p. 354. When white light passes through a colored stone, light of certain wavelengths is absorbed more strongly than others, the colors least absorbed combining to produce the color of the stone. When viewed through a spectroscope, the colors most strongly absorbed may show as dark bands crossing the spectrum in characteris- tic positions. Such a spectrum is known as an absorption spectrum, and provides a useful means of identification. Anderson.

abyssal realm

of the same wavelength. Strock, 10. abstract. To absorb the waters of a neighbor- ing stream by abstraction; said of water- courses. Standard, 1964. abstraction. In geology, the draining of water from a stream by another having more rapid corrading action. Standard, 1964. abteilung. a. Ger. A part or district of a mine assigned to the care of a fireman or deputy. Fay. b. Ger. A_ stratigraphical formation or series. Holmes, 1928. abundant vitrain. A field term denoting, in accordance with an arbitrary scale estab- lished for use in describing banded coal, a frequency of occurrence of vitrain bands comprising 30 to 60 percent of the total coal layer. Compare dominant vitrain; moderate vitrain; sparse vitrain. A.G.I. abutment. a. A surface or mass provided to withstand thrust, for example, the end sup- ports of an arch or bridge. In coal mining, (1) the weight of the rocks above a narrow roadway is transferred to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway; and (2) the weight of the rocks over a

longwall face is transferred to the front abutment, that is, the solid coal ahead of the face and the back abutment, that is,

the settled packs behind the face. See also pressure arch. Nelson. b. The structural portion of a furnace that withstands the thrust of an arch. A.RJ.

abutment load. In underground mining, the weight of rock above an excavation which has been transferred to the adjoining walls. Pryor, 3.

abysmal. See abyssal.

abysmal sea. That part of the sea which occupies the ocean basins proper. Fay.

abyss. a. A very deep, unfathomable place. The term is used to refer to a particularly deep part of the ocean, or to any part be- low 3,000 fathoms. H&G. b. Synonym for pit; pot; pothole; chasm; shaft. Schiefer- decker.

abyssal; abysmal. a. Of, or pertaining to, deep within the earth. Synonym for plu- tonic. A.G.I. b. Of, or pertaining to, the oceanic deeps below 1,000 fathoms (6,000 feet). A.GJ. c. Referring to the great depths of seas or lakes where light is ab- sent. A.G.J. d. In oceanography, relating to the greatest depths of the ocean; relating to the abyssal realm. C.T.D. e. Deep-sea region below the mean sphere level. Schie- ferdecker.

abyssal assimilation. See assimilation. Hess.

abyssalbenthic. A zone comprising all of the deep-sea benthic system below the archi- benthic zone, or below 800 to 110 meters. A.G.1.

abyssal deposit. A deposit of the deep sea, accumulating in depths of more than 1,500 fathoms of water; these deposits comprise the organic oozes, various muds, and red clay of the deepest regions. C.T.D.

abyssal injection. The process by which magmas, originating at considerable depths, are considered to have been driven up through deep-seated contraction fissures in the earth’s crust. Hess.

abyssal intrusion. An alternative name for a plutonic intrusion. C.T.D.

abyssal plain. a. An area of the ocean floor with a slope of less than 1 in 1,000. Schie-

absorption tower. A tower in which a liquid absorbs a gas. Bureau of Mines Staff.

absorptivity. The ratio of the radiant energy absorbed by a body to that falling upon it. It is equal to the emissivity for radiation

ferdecker. b. Flat, nearly level areas which occupy the deepest portions of many ocean basins. A.G.I.

abyssal realm. The deep waters of the ocean

below 1,000 fathoms, or 2,000 meters, or

abyssal realm

6,000 feet. Bureau of Mines Staff.

abyssal rock. A plutonic or deep-seated igne- ous rock. The word was suggested and especially used by Brégger. Fay.

abyssal theory. A theory of the origin of ores involving the separation of ore from silicates during the cooling of the earth from the liquid stage. A.G.I.

abyssal zone. The marine-life zone of the deep sea embracing the water and bottom below a depth of 6,000 feet. Stokes and Varnes, 1955.

Abyssinian gold. a. Talmi gold. Brass having a thin facing of gold applied by rolling. Used for costume jewelry. CCD 6d, 1961. b. A yellow- or gold-colored aluminum bronze containing 5 to 10 percent alumi- num, the remainder being copper. CCD 6d, 1961.

Abyssinian well. Pointed and _ perforated tube driven into the ground by a light pile- hammer, Water is extracted by pumping. Ham.

abyssobenthic. Relating to that part of the abyssal realm which includes the ocean floor; pertaining to or living on the ocean floor at great depths. C.T.D.

abyssolith. Literally, a bottomless body of rock material; a molten mass of eruptive material passing up without a break from the zone of permanently molten rock with- in the earth. A.G.I.

abyssopelagic. a. Relating to that part of the abyssal realm which excludes the ocean floor; floating in the depths of the ocean. C.T.D. b. Pertaining to that portion of the deep waters of the ocean which lie below depths of 2,000 meters (6,000 feet). A.G.I.

ac Abbreviation for alternating current; acid. Also abbreviated AC, a-c, ac. BuMin Style Guide, p. 58; Handbook of Chemistry and Physics, 45th ed., 1964, p. C-74; Zimmer- man, p. 7.

Ac Chemical symbol for actinium. Handbook of Chemistry and Physics, 45th ed., 1964, p. B-1.

acadialite. A reddish variety of chabazite. Dana.

Acadian. A series name applied to the Mid- dle Cambrian strata of the Atlantic Prov- ince in North America (Newfoundland, Nova Scotia to eastern Massachusetts). C.T.D.

Acadian orogeny. Late Devonian diastro- phism. A.G.I. Supp.

acanthite. A silver sulfide, AgeS; monoclinic ; color and streak, blackish lead-gray; Mohs’ hardness, 2 to 2.5; specific gravity, 7.2 to 7.3. Dana 17. Contains 87 percent silver. Sanford.

acarreos. a. Mex. Float rock. Fay. b. Mex. Drift composed of rounded rocks, pebbles, and gravel. Fay.

acaustobiolith. a. An incombustible sedi- ment resulting from biologic activity, for example, limestone. A.G.I. b. Noncombus- tible, organic deposits of purely mineral character. A.G.I.

acaustophytolith. A rock formed wholly from pure accumulation of organically produced mineral matter, such as those formed from diatoms (silica) and nummulites (calcite). A.G.I,

accelerated weathering test. A test to indi- cate the effect of weather on coal, in which the coal is alternately exposed to freezing, wetting, warming, and light; the alterna- tion may be varied to suit. This test may be applied to other bituminous material. Hess,

accelerating points. Each position of an

electric controller which increases the cur- rent through the motor is known as an ac- celerating point. NEMA MBI1-1956.

acceleration. That due to the gravitational attraction of the earth is 980.665 centi- meters per square second (32.174 feet per- square second) for a free-falling body in vac- uum. International Committee on Weights and Measures. True value varies slightly with isotatic effect, latitude, longitude, and the departure of the planet from a truly spherical shape. Pryor, 3.

accelerator. a. A machine that accelerates electrically charged atomic particles to high velocities. Electrons, protons, deuterons, and alpha particles can be accelerated to nearly the speed of light for use in nuclear research. Types of accelerators include the betatron, cyclotron, linear accelerator, and synchrotron. Familiarly known as atom smasher. L@L. b. In the case of stucco, plaster, mortar, concrete, etc., a substance which will hasten the set. ASTM C11-60. c. A device controlling the rate at which fuel is injected into a combustion-type en- gine and hence controlling its speed. Also called throttle. Long. d. A substance added to increase the rate of a chemical reaction. See also catalyst. Nelson.

accelerometer. An instrument used to meas- ure acceleration ; specifically, a seismograph designed to measure earth particle accel- erations. A.G.I.

acceptance operations. In mineral processing, rejection of material hoisted as run-of-mine ore because of inferior quality, Bureau of Mines Staff.

acceptor levels. Energy levels formed within Ae energy gap by a deficiency of electrons. VV.

accessory. a. Applied to minerals occurring in small quantities in a rock. The presence or absence of these minor minerals does not affect the classification or the naming of the rock. Holmes, 1928. b. Fragments de- rived from previously solidified volcanic rocks of related origin, that is, the debris of earlier lavas and pyroclastic rocks from the same cone. See also accessory mineral, b. Bureau of Mines Staff. c. In a strict sense, only those tools or small parts, etc., normally supplied with a drill machine by the manufacturer without their being spe- cifically ordered by the buyer of the drill. In a general sense, the term is commonly and synonymously used for auxiliary. See also auxiliary, a. Long

accessory ejecta. Pyroclastic materials de- rived from previously solidified . volcanic rocks of consanguineous origin, that is, the debris of earlier lavas and pyroclastic rocks from the same cone. Such ejecta corre- spond to the materiaux paleogenes of La- croix. A.G.I.

accessory elements. Synonym for minor ele- ments; trace elements. A.G.I.

accessory mineral. a. One of those mineral constituents of a rock that occur in such small amounts that they are disregarded in its classification and definition. Opposite of essential mineral. Fay. b. Primary type min- erals which were associated with the parent clay-forming material usually mica, feld- spar, and quartz, (that is, decomposition of granite to kaolin with accessory minerals mica, feldspar, and quartz. Bureau of Mines Staff.

accessory plate. a. The quartz wedge insert- ed in the microscope substage above the polarizer in order to estimate birefringence and to determine optical sign of uniaxial

acclinal valleys

minerals. Pryor, 3. b. The selenite plate which gives the sensitive tint of a specimen between crossed nicols. Pryor, 3. c. The mica plate which retards yellow light. Pryor, 3.

access road. A route constructed to enable plant, supplies, and vehicles to reach a mine, quarry, or opencast pit. In remote and isolated regions, the provision of. an access road may be very costly. Nelson.

access time. That required to locate data in the memory. Pryor, 3, p. 31.

accident. Gr. Brit. An incident or event at work in which someone sustains a bodily injury which causes the injured person to be away from work for more than three days. A certain degree of harm to an indi- vidual is the criterion. The event is then usually classified as a fatal, a serious non- fatal, or a minor or plus 3-day accident. Se also near accident. Nelson.

accidental. A broken fragment derived from volcanic rock, not of the magma involved during an eruption, but from other igne- ous, metamorphic, or sedimentary rocks through which the vent was developed Hess.

accidental block. A solid chip of igneous, metamorphic, or sedimentary rock torn from the subvolcanic basement and ejected from a volcano. Synonym for noncognate block. A.G.I.

accidental error. Unpredictable, arising from special cause. Pryor, 3, p. 159.

accidental inclusion. An enclosed crystal or fragment having no genetic connection with the igneous rocks in which they occur, See also accidental. Hess.

accidental pearl. Genuine natural pearl as distinguished from (artificially induced) cultured pearl. A term not used in the trade as it is of questionable meaning. Shipley.

accident-cause code. A system sponsored by the American Standards Association. Under this code accidents are classified under eight defective working conditions and nine improper working practices. Nelson.

accident frequency rate. The number of all disabling injuries (fatal, permanent-total, permanent-partial, and temporary lost-time injuries) per million man-hours of ex- posure. Hess.

accident-prone. Accident statistics reveal that certain individuals have a predisposition to sustain more accidents than others ex- posed to the same hazard. This suggests that there is a certain defect or propensity in some miners which makes them acci- dent-prone cases. It is also suggested that such cases tend to sustain an undue num- ber of injuries even at home or at sports. Nelson.

accident severity rate. The number of days of disability resulting from all injuries (fatal, permanent-total, permanent-partial, and temporary lost-time injuries) per thou- sand man-hours of exposure. Hess.

acclimatization. A man completely new to a hot mine will find great difficulty in doing any appreciable amount of work, Within a short period, his body will have improved its mechanism for heat loss, the rate at which the man can sweat will be much increased, pulse rate decreases, body tem- perature falls, and the man is then said to be ‘“‘acclimatized” to hot working condi- tions. A minority never become acclima- tized and are said to be “‘heat intolerant.” Roberts, I, p. 132.

acclinal valleys. Those that run in the direc-

acclinal valleys

tion of the dip. A.G.I.

accompt. a. (Corn.) Account day; the usual settling day. Fay. b. The place of meeting, or account house. Fay.

accordant tributary. A tributary that enters the main trunk stream at grade, that is, at the same elevation as the main stream. Stokes and Varnes, 1955.

accordion roller conveyor. A roller conveyor with a flexible latticed frame which per- mits variation in length. ASA MH4,1— 1958.

account. The record of the transactions af- fecting one party; as any one party may be the receiver or debtor in one transac- tion and the giver or creditor in another, an account has two sides, a debtor and a creditor side. Truscott, p. 280.

accountancy. The continuous recording of transactions on a money basis in a manner to show clearly at any time the financial position of a business, what profit or loss has been made over any period, and where that profit or loss was made. Truscott, p. 280.

account day. See bill day. Nelson.

accretion; aggradation. a. The process by which inorganic bodies increase in size by the addition of fresh particles to the out- side. Fay. b. The gradual addition of new land to old by the deposition of sediment carried by the water of a stream. A.G.J. c. May be either natural or artificial. Nat- ural accretion is the gradual buildup of land over a long period of time solely by the action of the forces of nature, on a beach by deposition of waterborne or air- borne material. Artificial accretion is a similar buildup of land by reason of an act of man, such as the accretion formed by the groin, breakwater, or beach fill depos- ited by mechanical means. H&G.

accretionary lapillus. A pellet, often exhibit- ing concentric structure owing to the ac- cretion of fine ash or dust around raindrops falling through an explosion cloud, or to similar accretion around a nucleus frag- ment which rolls along the ground. Accre- tionary lapilli are also called mud pellets; pisolites. A.G_I.

accretionary lava balls. Rounded balls of lava found on the surfaces of many aa flows, formed by the rolling up and ad- hesion of viscous lava around some frag- ment of solidified lava as a center. A.G.I.

accretionary limestone. A limestone which has formed in place by slow accumulation of organic remains. Many such deposits belong to the reef or bioherm subclass. A.G.I.

accretion coast. See shoreline of prograda- tion. Schieferdecker.

accretion hypothesis. Any hypothesis of the origin of the earth which assumes that it has grown from a small nucleus by the gradual addition of solid bodies, such as meteorites, asteroids, or planetesimals, for- merly revolving about the sun in independ- ent orbits, but eventually drawn by gravi- tation to the earth and incorporated in it. Fay.

accretion vein. A vein formed by the repeat- ed filling of a channelway and its reopen- ing by the development of fractures in the general zone undergoing mineralization. Forrester, p. 115.

accumulation. a. In coal mining, bodies of firedamp that tend to collect in higher parts of mine workings and at the edge of goaves and wastes. They are found in cav- ities, at ripping lips, at other sheltered

places protected from the ventilating cur- rent, and at the higher sides of rise faces. Mason, v. 1, p. 262. b. The concentration or gathering of oil or gas in some form of trap. Commercial accumulation is a vol- ume or quantity sufficient for profitable exploitation. A.G.J. c. A collected mass of material. Jones.

accumulator. a. A cylinder containing water

or oil under pressure of a weighted piston for hydraulic presses, hoists, etc. It is be- tween the pumps and the presses, keeps a constant pressure on the system, and ab- sorbs shocks. Bureau of Mines Staff. b. A storage battery. Bureau of Mines Staff. c. In oceanography, a spring of rubber or steel attached to a trawling warp, to lessen any sudden strain due to the trawl catch- ing GelnDs

accumulator conveyor. Any conveyor de-

signed to permit accumulation of packages or objects. Usually roller, live roller con- veyor, roller slat conveyor, or belt con- veyors. ASA MH4.1-1958.

accumulator metal. An alloy of 90 percent

lead, 9.25 percent tin, and 0.75 percent antimony; condenser toil. Campbell.

accumulator plant. In geobotanical prospect-

ing, a plant or tree that acquires an ab- normal content of a metal where growing in metal-bearing soil. A.G.I.

accuracy. a. The practical limit of accuracy

in building work is about one-eighth of an inch for placing of walls and floors, and about 1 inch for a long tunnel driven through a mountain. A modern air survey, plotted to a scale of 1 in 500, can give an accuracy of plus or minus 3 inches verti- cally or horizontally. Ham. b. The close- ness of approach of a measurement to the true value of the quantity measured. Since the true value cannot actually be meas- ured, the most probable value from the available data, critically considered for sources of error, is used as the truth. Compare precision. ASM Gloss.

accuracy of a method. A measure of the

ability of a method to provide accurate results, that is, results which are precise and free from bias. The accuracy of a method must not be confused with its pre- cision. A determination may be made with great precision, and the standard deviation of a number of determinations on the same consignment of coal may therefore be low, but the results will only be accurate if they are free from bias. B.S. 1017, 1960, Pele

accuracy of a result. The closeness of agree-

ment between an experimental result and the true value. B.S. 1017, 1960, Pt. 1.

acerado. Mex. Gray copper ore; any gray

steely ore. Fay.

acetamide; acetic acid amide; acetic acid

amine; ethanamide. Colorless; deliques- cent crystals; mousy odor; CHsCONHz2. Used in explosives and as a soldering flux. CCD 6d, 1961.

acetic acid; ethanoic acid. Produced during

the dry distillation of wood followed by alkali and acid (sulfuric) treatment and further distillation; by the oxidation of diluted alcohol (HC:HsO:z) ; specific grav- ity, 1.0492 (at 20° C, referred to water at 4° C). Vinegar is a preparation of acetic acid and it contains a legal minimum of 4 percent of acetic acid. Used in the porce- lain enameling industry to prepare grain- ing-board surfaces and for analytical work. Hansen.

acetic acid amine; acetamide; acetic acid

acicular

amide; ethanamide. See acetamide. CCD 6d, 1961.

acetone; dimethyl ketone; 2-propane. A flam- mable liquid; CsHeO. Used widely in in- dustry as a solvent for many organic sub- stances. Shell Oil Co.

acetylene; ethyne; ethine. The most brilliant of illuminating gases; C2He It may be produced synthetically from its elements, by incomplete combustion of coal gas, and commercially from calcium carbide (CaCsz) by reaction with water. Standard, 1964. Used in manufacturing explosives. Bennett 2d, 1962. Also used formerly as an illumi- nating gas in mines and around drill rigs. When combined with oxygen, acetylene burns to produce an intensely hot flame and hence now is used principally in weld- ing and metal-cutting flame torches. Long.

acetylene black. Graphitic type of carbon black obtained by incomplete combustion of acetylene; apparent density, 0.21. Ben- nett 2d, 1962.

acetylene lamp. See carbide lamp. Zern.

acetylene tetrabromide; symmetrical tetra- bromoethane; Muthmann’s liquid. Yellow- ish liquid; CHBreCHBre; specific gravity, 2.98 to 3.00; boiling point, 239° to 242° C with decomposition (at 760 mm); also, boiling point, 151° C (at 54 mm) ; melting point, 0.1° C; and refractive index, 1.638. Used for separating minerals by specific gravity; a solvent for fats, oils, and waxes; a fluid in liquid gases; and a solvent in microscopy. CCD 6d, 1961.

acetylite. Calcium carbide treated with glu- cose to give a slower and more uniform production of acetylene gas than can be obtained from the untreated calcium car- bide. Crispin.

achavalite. Iron selenide, FeSe, occurring with other selenides at Cacheuta, Argen- tina. Spencer 18, M.M., 1949.

Acheson furnace. A resistance-type furnace for the production of silicon carbide and synthetic graphite. Henderson.

Acheson graphite. Artificial graphite made from coke by electric furnace heating. Bennett 2d, 1962.

Acheson process. A process for the produc- tion of artificial or synthetic graphite. It consists of sintering pulverized coke in the Acheson furnace at 5,000° to 6,000° F. Henderson.

achiardite. Same as dachiardite. English.

achirite. Same as dioptase. Standard, 1964.

achondrite. A rare, stony meteorite without chondrules. A.G.J. Supp.

achrematite. A pale sulfur-yellow to orange and red arsenochlormolybdate of lead, 35Pb0.3PbCl2.9As20s.4Mo0s; Mohs’ hard- ness, 3 to 4; specific gravity, 5.965. From the mines of Guanacere, Chihuahua, Mex- ico. Hess.

el ee A colorless variety of tourmaline.

ay.

achromatic. Free from hue. See also achro- matic color; achromatic loupe. Shipley.

achromatic color. White, black, or any tone of neutral gray, that is, gray containing no tinge of any hue. See also chromatic color. Shipley.

achromatic loupe. Any loupe containing an achromatic lens. Shipley.

achromatic triplet. A loupe corrected for Go aberration. See also loupe. Ship- ey.

achua. A Chilean term for a small earthen- ware dish used in making tests in the patio process. Hess.

acicular. A mineral consisting of fine needle-

acicular

like crystals, for example, natrolite. Nelson.

acicular bismuth; aciculite. Synonym for aikinite. Hess.

acicular powder. In powder metallurgy, needle-shaped particles. ASM Gloss.

acid. a. Sharp or biting to the taste; sour. Having acid-forming constituents present in excess of the proportion required to form a neutral or normal compound. Webster 3d. b. A compound that dissociates in a water solution to furnish hydrogen ions. ASTM STP No. 148-D. c. A substance which tends to lose a proton. C.T.D. d. A substance containing hydrogen which may be replaced by metals with the formation of salts. C.T.D. e. In geology, a test for composition of rocks. Application of strong acid dissolves carbonates and other compo- nents, leaves silica. Hy. f. See acidic, a.

acid anhydride. An oxide of a nonmetal, so called because such an oxide may be formed from an acid by the abstraction of water; for example, SOs is the anhydride of H2SQ,. A.G.I.

acid annealing. An annealing process in which ferrous metal shapes are coated with acid before and in conjunction with the annealing. ASTM C286-65.

acid bath. A vessel containing an acid solu- tion strong enough to attack and dissolve the diamond-matrix metal in a worn or dull bit crown, thereby releasing the dia- monds, which can be recovered and reset in another bit or reused in some other manner. Long.

acid Bessemer converter. One liner with acid refractories. Bureau of Mines Staff.

acid bottle. Acid-dip bottle used in survey of boreholes. A soda-lime glass tube charged with dilute hydrofluoric acid, left in the borehole for 20 to 30 minutes to measure inclination. May be fitted in a clinometer. Pryor, 3. Also called acid-dip bottle; acid- dip test tube; acid-etch tube; acid-etch vial; acid-test tube; acid tube; acid vial; angle-test tube; culture tube; etch tube; sargent tube; vial. See also acid-dip survey. Long.

acid bottom and lining. The inner bottom and lining of a melting furnace consisting of materials like sand, siliceous rock, or silica brick that give an acid reaction at the operating temperature. ASM Gloss. See also acid refractories.

acid bronze. An acid-resisting alloy some- times used for mine pumps. It is said to contain 1.5 percent nickel, 17.0 percent lead, 8.0 percent tin, and 73.5 percent copper. Camm.

acid calcium phosphate. See calcium phos- phate, monobasic. CCD 6d, 1961.

acid clay. a. A naturally occurring clay which, after evaluation, usually with acid, is used mainly as a decolorant or refining agent, and sometimes as a desulfurizer, coagulant, or catalyst. Institute of Petro- leum, 1961. b. A clay which yields hydro- gen ions in a water suspension. A hydrogen clay. Hess.

acid coke. A byproduct obtained in treating dry run tar, at an elevated temperature with sulfuric acid; it is a soft, solid coke containing free carbon, complex heavy hydrocarbons, free sulfur, and _ sulfuric acid. Hess.

acid copper. a. Copper electrodeposited from an acid solution of a copper salt, usually copper sulfate. ASM Gloss. b. The solu- tion referred to in definition a. ASM Gloss.

acid cure. In uranium extraction, sulfation of moist ore before leach. Pryor, 3.

264-972 O-68—2

acid-dip bottle. Synonym for acid bottle. Long.

acid-dip survey. A method of determining the angular inclination of a borehole in which a glass, test-tubelike bottle partly filled with a dilute solution of hydro- fluoric acid is inserted in a watertight metal case. When the assemblage is low- ered into a borehole and left for 20 to 30 minutes, the acid etches the bottle at a level plane from which the inclination of the borehole can be measured. Also called acid-dip test; acid test. Long.

acid-dip test. Synonym for acid-dip survey.

Long.

acid-dip test tube. Synonym for acid bottle. Long.

acid electric furmace. An arc furnace having an acid refractory hearth. Bureau of Mines Staff.

acid embossing. The etching of glass with HF or a fluoride. Dodd.

acid embrittlement. A form of hydrogen em- brittlement which may be induced in some metals by acid treatment. ASM Gloss.

acid-etch tube. Synonym for acid bottle. Long.

acid-etch vial. Long.

acid flux. Metallurgically acid material (usu- ally some form of silica) used as a flux. Bennett 2d, 1962.

acid frosting. The etching of glass hollow ware with HF or a fluoride. Dodd.

acid gold. A form of gold decoration for pottery introduced in 1863 by Mintons Ltd., Stoke-on-Trent, England. The glazed surface is etched with dilute HF prior to application of the gold; the process de- mands great skill and is used for the dec- oration only of ware of the highest class. A somewhat similar effect can be obtained by applying a pattern in low-melting flux on the glaze and gold-banding on the fluxed area; this is known as mock acid gold. Dodd.

acidic. a. Applied to those igneous rocks con- taining more than 66 percent SiOz, con- trasted with intermediate and basic. Some- times loosely and incorrectly used as the equivalent of felsic and of oversaturated, but these terms include rock types (for example, nepheline syenite and quartz basalt, respectively) which are not gen- erally considered acidic. Fay. b. Less fre- quently used in reference to the compo- sition of feldspars, based on their content of silica. A.G.I. c. When referring to hy- drothermal, pegmatitic, or other aqueous fluids, the term is used in its chemical sense of high hydrogen ion concentration (low pH); very loosely used in reference to solutions containing salts of the strong acids (chlorides, sulfates, etc.) regardless of pH. A.G.J. d. In furnace practice, a slag in which silica is present in excess of the amount required to form a neutral slag with the earthy bases present. A.G.I.

acidic oxide; acid anhydride. The oxide of a nonmetal that reacts with water. to form an acid; for example, sulfur dioxide, SOz. Bennett 2d, 1962.

acidic salts. These contain replaceable hy- drogen and are formed when a polybasic acid reacts with a quantity of a base in- sufficient to replace the whole of the re- placeable hydrogen. Cooper.

acidimetry. a. The determination of the con- centration of acid solutions or of the quan- tity of acid in a sample or mixture. This is usually done by titration with a solution

Synonym for acid bottle.

acid polishing

of base of known strength (standard solu- tion) and an indicator is used to establish the end point. See also pH. CCD 6d, 1961. b. The determination of the quantity of acid in a solution. Hansen.

acid ion. One which forms an acid molecule through combination with one or more protons. Pryor, 3.

acidity. The extent to which a solution is acid. See also pH. C.T.D.

acidity coefficient. See coefficient of acidity.

acidization. The process of forcing acid into a limestone, dolomite, or sandstone in order to increase permeability and porosity by dissolving and removing a part of the rock constituents. It is also used to remove mud injected during drilling. The general ob- jective of acidization is to increase pro- ductivity. A.G.I.

acidize. To treat a limestone or dolomitic formation with dilute hydrochloric acid to enlarge its void spaces. Wheeler.

acidizing. See acidization. Institute of Pe- troleum, 1961.

acid-jointing. Special use of certain asbestos varieties. Sinclair, W. E., p. 483.

acid leach. a. Metallurgical process for dis- solution of uranium values by means of acidulated solution (used on sandstone ores of low lime content). Ballard. b. In uranium extraction, dissolution of uraninite in presence of sufficient oxygen to render accompanying iron ferric, satisfying the equation: 2U;0s + 6HSO,. + O26UO2 SO. + 6H2O. Pryor, 3.

acid lining. See acid bottom and lining.

acid metal. An alloy intended to resist cor- rosion by acids; contains 88 percent cop- per, 10 percent tin, and 2 percent lead. Campbell.

acid mine drainage. Acidic drainage from bituminous coal mines containing a high concentration of acidic sulfates, especially ferrous sulfate. ASTM STP No. 148-D.

acid mine water. a. Mine water which con- tains free sulfuric acid, mainly due to the weathering of iron pyrites. A pit water, which corrodes iron pipes and pumps, usu- ally contains a high proportion of solids per gallon, principally the sulfates of iron, chiefly ferrous and alumina. Nelson. b. Where sulfide minerals breakdown under chemical influence of oxygen and water, the mine drainage becomes acidic and can corrode ironwork. If it reaches a river sys- tem, biological damage may also result. Pryor, 3.

acid neutralizers. Calcium carbonate (Ca- CO;), magnesium carbonate (MgCOs), and china clay, which neutralize free acids, thereby preventing explosives from decom- posing in storage. They also have a cooling effect and tend to reduce the sensitivity of the explosive. Cooper, p. 345.

acid number. Milligrams of K.OH required to neutralize the free fatty acids in 1 gram of material. Pryor, 3.

acid open-hearth furnace. An open-hearth furnace used in the refining of hematite iron; little such iron is now made. The particular feature is that the hearth is made of acid refractories—silica bricks covered with a fritted layer of silica sand. Dodd.

acid open-hearth steel. Low-phosphorus pig iron treated in an acid (silica or sand)- lined furnace. Mersereau, 4th, p. 481.

acid ores. Siliceous ores. Newton, Joseph. Introduction to Metallurgy, 1938, p. 205.

acid polishing. A method of polishing cut decorations on glassware by immersing the

acid polishing

article in an acid bath for a few minutes, rinsing in water and brushing out the cut parts. C.T.D. acid process. a. A steelmaking process, either Bessemer, open-hearth, or electric, in which the furnace is lined with a siliceous re- fractory, and for which pig iron low in phosphorous is required, as this element is not removed. See also basic process. C.T.D. b. One which employs an acid slag. Bureau of Mines Staff. acidproof brick. Brick having low porosity and permeability, and high resistance to chemical attack or penetration by most commercial acids and some other corrosive chemicals. HW. acid radical. That part of the acid which cannot be replaced by a metal; for exam- ple, SO, in sulfuric acid (H2SOx). Cooper. acid-recovery operator. In the coke products industry, one who recovers sulfuric acid used in processing coke-gas byproducts by cooking sludge with steam in acid regen- erator pots. Also called acid regenerator. D.O.T. Supp. acid refractories. Refractories containing a substantial amount of silica that may react chemically with basic refractories, basic slags, or basic fluxes at high temperatures. ASTM C-71-64. acid refractory material. A general term for those types of refractory material that con- tain a high proportion of silica, for exam- ple, silica refractories (greater than 92 percent SiOz) siliceous refractories (78 to 92 percent SiOz). The name derives from the fact that silica behaves chemically as an acid and at high temperatures reacts with bases such as lime or alkalies. Dodd. acid refractory products. Forming those made of clay-silica mixtures or pure silica. Rosenthal. acid regenerator. See acid-recovery operator. D.O.T, Supp. acid resistance. The degree of resistance of the ceramic surface to attack by acids, (that is, porcelain enamels, chemical stone- ware, glazes, etc.). Bureau of Mines Staff. acid resistance of vitreous enamelware. In the United States the acid resistance of vitreous enamelware at (nominal) room temperature is determined by exposing the enameled surface to 10 percent citric acid for 15 minutes at 80° F ASTM C282. Five classes of enamelware are distinguished ac- cording to their subsequent appearance: AA: no visible stain and passes dry-rub- bing test; A: passes blurring-highlight test and wet-rubbing test;

B: passes blurring-highlight test; fails wet-rubbing test; C: fails blurring-highlight test; passes

disappearing highlight test; D: fails disappearings highlight test.

Dodd.

acid-resistant brick. Brick suitable for use in contact with chemicals usually in conjunc- tion with acid-resistant mortars, ASTM C43-65T.

acid rock. Loosely used in petrology, gen- erally to mean one of the following: (1) An igneous rock containing 66 percent or more of silica, free or combined, in this sense being nearly equivalent to acidic; (2) an igneous rock in which minerals high in silica, such as quartz, alkaline feld- spar, and muscovite are dominant; and (3) very loosely, an igneous rock composed dominantly of light-colored minerals. In all three senses contrasted with basic. The

term is misleading, undesirable, and _ be- coming obsolete. As used in the first sense, it is being replaced by silicic or persilicic; as used in the second sense, it should be replaced by felsic or a term denoting the dominant mineral; and as used in the third sense, it should be replaced by leucocratic. See also acidic, a. Fay.

acid salt. a. A salt containing hydrogen, (for example, KHSQ,). A.G.I. b. A salt which dissolves to yield a solution containing an excess of H+ ions over OH~— ions, whether or not it contains hydrogen in its formula, (for example, FeCls). A.G.I.

acid-scaling. Raw shapes dipped in acid or sprinkled with acid and annealed. Bryant.

acid slag. One which contains substantial amounts of active silica. Bureau of Mines Staff.

acid sludge. Products of refining of tar, shale oil, petroleum in which sulfuric acid reacts to form a sulfonic acid mixture, green acids, and mahogany acids and salts. Used in the flotation process, and in proprietary collector agents for flotation of iron ores. Pryor, 3.

acid soil. A soil deficient in available bases, particularly calcium, and gives an acid reaction when tested by standard methods. Stokes and Varnes, 1955,

acid steel. Steel melted in a furnace with an acid bottom and lining and under a slag containing an excess of an acid substance, such as silica. ASM Gloss. See also acid process.

acid, strength of. Related to ability to liber- ate hydrogen ions to solution, and hence- to-electrical conductivity of equivalent

aqueous solutions of acids. Pryor, 3.

acid sulfate. Compound containing or dis- sociating to give the ion, HSOu. Pryor, 3

acid test. a. Synonym for acid-dip survey. Long. b. A severe or decisive trial, as of usability or authenticity. Long.

acid tube. Synonym for acid bottle. Long.

acid treatment. The process of agitating petroleum products with sulfuric acid to remove undesirable compounds. Hess.

acid tube. Synonym for acid bottle. Long.

acidulae. Cold mineral waters, especially those impregnated with carbonic acid. Fay.

acid vial. Synonym for acid bottle. Long.

acid-vial culture tube. Synonym for acid bottle. Long.

acid water. Water charged naturally with carbon dioxide. Also applied to natural waters containing sulfur compounds, espe- cially sulfates. Bureau of Mines Staff.

acieral. An alloy containing 92 to 97 per- cent aluminum and offered as a metal of strength and lightness and noncorrosive, suitable for use in the construction of automobiles, aircraft, military equipment, railroad cars, valves, hardware, and for the manufacture of helmets. It is silver white, and has a specific gravity of 2.82 and a melting point of 1,382° F. Its tensile strength in castings is given as 30,000 pounds per square inch, and in rods and sheets as 28,000 to 64,000 pounds and heat-treated as upward of 70,000 pounds per square inch. Fay.

aciform. Needle- Boel, Shipley.

aciniform. From the Latin acinus, meaning grape or grapestone. A mineral aggregate or a cluster of minerals shaped like a cluster of grapes, or clustered like grapes. Also, full of small kernels like a grape. Bureau of Mines Staff.

acimose. a. Grapelike; applied to the struc- ture of clustered mineral aggregates. Syn-

acoustic axis

oynm for aciniform; acinous. Bureau of Mines Staff. b. Granulated; like grape seeds; applied to the texture of some mineral aggregates. Bureau of Mines Staff.

acinous. Synonym for aciniform; acinose. Bureau of Mines Staff.

aclinal; aclinic. Having no inclination or dip; situated where a magnetic needle if suspended freely has no dip or inclination and assumes a horizontal position, as the aclinic line or magnetic equator. Webster, 3d.

aclinic line; dip equator; magnetic equator. The line through those points on the earth’s surface at which the magnetic in- clination is zero. The aclinic line is a particular case of an isoclinic line. H&G.

ACL kiln; Lepol kilm. ACL is a trademark of the Allis-Chalmers Manufacturing Com- pany in the United States. Lepol is a trademark of Polysius Company, Germany. Both terms refer to a traveling grate pre- heater for a portland cement batch prior to its being fed to a rotary cement kiln; with this attachment, the length of a rotary cement kiln can be halved. Dodd.

acme thread. A screw thread, the section of which is between the square threads and the V threads. Used extensively for feed screws. Crispin.

acmite. A brown or green silicate of sodium and iron, essentially NaFe ’ ’ ’ (SizOs), belonging to the pyroxene group and often found in long prismatic crystals charac- teristically pointed. The variety aegirite, which is common in certain igneous rocks, occurs in bluntly terminated crystals and also in capillary and fibrous forms. Web- ster 2d. Monoclinic; Mohs’ hardness, 6 to 6.5; specific gravity, 3.5. Dana 17.

acmite trachyte. A trachyte in which the pyroxene is acmite or aegirine and the feldspar is anorthoclase. It differs from normal trachyte in that its predominant alkali is soda instead of potash. Acmite trachyte is intermediate between true trachyte and phonolite. First described from the Azores and also found in the Crazy Mountains, Mont. Fay.

acopolado. Mex. Ore containing 50 to 60 ounces of silver per ton. Hess.

acoustic. Used when the term which it modi- fies designates something which has the properties, dimensions, or physical charac- teristics associated with sound waves. Hy.

acoustic absorptivity. The ratio of the sound energy absorbed by a surface to that incident upon it. Hess.

acoustical. The adjective acoustical is used when the term being qualified does not innately contain some property, dimension, or physical characteristic which is inti- mately associated with sound. Hy.

acoustical well logging. Any determination of the physical properties or dimensions of a borehole by acoustical means, includ- ing measurement of the depth of fluid level in a well. A.G.I.

acoustic attenuation log. In theory, a log designed to measure the manner in which the energy of elastic waves is dissipated in passing through rock. Although no prac- tical log of this type has yet evolved, the belief that a log of this parameter would permit the estimation of the permeability of formations would seem to insure such a development since no log has been de- veloped to record permeability. Wyllie, p. 169.

acoustic axis. See axis of acoustic symmetry. H&G.

acoustic dispersion

acoustic dispersion. Acoustic dispersion is the change of speed of sound with fre- quency. H&G.

acoustic impedance. The acoustic impedance of a given surface area of an acoustic medium perpendicular, at every point, to the direction of propagation of sinusoidal acoustic waves of given frequency, and having equal acoustic pressures and equal volume velocities per unit area at every point of the surface at any instance, is the quotient obtained by dividing (1) the phasor corresponding to the acoustic pres- sure by (2) the phasor corresponding to the volume velocity. H&G.

acoustic intensity. The limit approached by the quotient obtained by dividing the power of the acoustic energy being trans- mitted at a given time through a given area by the magnitude of this area as the magnitude of this area approaches zero. H&G.

acoustic interferometer. An acoustic inter- ferometer is an instrument for making phy- sical observations upon standing waves. It may be used, for example, to measure velocity, wave length, absorption, or im- pedance. H&G.

acoustic log. A continuous record made in a borehole showing the velocity of sound waves over short distances in adjacent rock; velocity is related to porosity and nature of the liquid occupying pores. A.G.I. Supp.

acoustic methanometer. An instrument to determine the concentrations of methane at points in the underground firedamp drainage pipes. It is based on the principle that sound travels much more rapidly in methane than in air and the intermediate velocity in a simple mixture can be used as a measure of the proportion of the two gases. A range of 40 to 90 percent methane is usually covered. New regula- tions which became effective in July 1961 call for automatic shutdown of methane drainage plants if the drained gas falls below 40 percent methane. Nelson.

acoustic radiation pressure. The acoustic radiation pressure is a unit directional steady-state pressure exerted upon a sur- face exposed to an acoustic wave. Such a steady pressure is usually quite small in magniture and is really observable only in the presence of very intense sound waves. H&G

acoustic radiometer. An instrument for meas- uring acoustic radiation pressure by deter- mining the unidirectional steady-state force resulting from reflection or absorption of a sound wave at its boundaries. H&G.

acoustic resistance. Product of longitudinal wave velocity and density, being the prop- erty that controls the reflective power at a boundary plane. Schieferdecker.

acoustics, The science of sound, including its production, transmission, and effects. Hy.

acoustic scattering. The irregular reflection, refraction, or diffraction of sound waves in many directions. Hy.

acoustic sounding. The indirect evaluation of water depth, using the principle of measuring the length of time necessary for a sound wave to travel to the bottom, reflect and travel back to the water surface. H&G.

acoustic strain gage; sonic gage. An instru- ment for measuring strains, for example, in concrete linings to shafts or roadways. It contains a length of fine wire under tension, the tension being varied by the

strain to which the gage is subjected. The measurement made is that of the frequency of vibration of the wire when it is plucked by means of an electromagnetic impulse and this measurement can be made with great accuracy. The gage is highly stable and readings can be made over a period of years without any fear of zero drift. See also electrical resistance strain gage; mechanical extensometer. Nelson.

acoustic theodolite. An instrument designed to provide a continuous vertical profile of ocean currents from the bottom to the surface in a specific location. H&G.

acoustic waves. a. The waves which contain sound energy and by the motion of which sound energy is transmitted in air, in water, or in the earth. The wave may be described in terms of change of pressure, of particle displacement, or of density. A.G.I, b. Used increasingly to study the physical properties of rocks, and composi- tion of gases. Investigations may be made both in situ and in the laboratory. Nelson.

Ac-plane. In structural petrology, a plane at right angles to the surface of movement. The ac-plane contains a, the direction of tectonic transport, and c, the axis per- pendicular to the surface of movement. A.G.I.

acre. a. A measure of surficial area, usually of land. The statute acre of the United States and England contains 43,560 square feet (4,840 square yards or 160 square rods); abbreviation, a. The so-called Scotch acre contains about 6,150 square yards, and the Irish acre 7,840. There are various special or local acres in England (as in Cheshire or among the hop grow- ers), varying from 440 to more than 10,- 000 square yards. Standard, 1964. b. Can. In Quebec, a linear measure that equals the square root of 43,560, or ap- proximately 208.7 feet. Fay. c. For the calculation of coal reserves, a convenient rule is to allow 1,200 tons per foot (coal thickness) per acre. For known and de- pendable areas, 1,500 tons per foot per acre may be used. Nelson.

acreage rent. Royalty or rent paid by the lessee for working and disposing of min- erals at the rate of so much per acre. Fay.

acre-foot. The quantity of water that would cover 1 acre, 1 foot deep. An acre-foot contains 43,560 cubic feet. Seelye, 1.

acre-inch. The volume of water, soil, or other material that will cover 1 acre, 1 inch deep. A.GJ.

acre-yield. The average quantity of oil, gas, or water recovered from 1 acre of a reservoir. The quantity of any product obtained from 1 acre. A.GJ.

acrobatholithic. a. Pertaining to a stage in the erosion of a batholith in which the summits of cupolas and stocks are exposed but the surface separating the barren in- terior of the batholith from the mineralized upper part is not exposed. Essentially, all metals are found in one place or another around cupolas exposed in this manner. A.G.I, b. Pertaining to a stage in the ero- sion of a batholith. Cupolas are exposed but erosion has not proceeded deep enough to reveal large areas of the interior. A.G.I. c. Applied to mineral deposit found in or near a summit cupolas of a batholith of which large areas of the interior are not yet exposed by erosion. Schieferdecker.

Acrocephalus robertii. A copper flower or copper indicator plant found in the Ka- tanga area of the Republic of the Congo,

actinium C

immediately north of the Rhodesian Cop- perbelt. It is reported as a small annual mint whose resistance to toxicity appears to be infinite. Hawkes, 2, p. 312.

acrometer. An instrument for determining the density of gases. Hess.

acromorph. Synonym for salt dome. A.G.I.

A-cropping. Scot. Toward the outcrop. Fay.

acrotomous. In mineralogy, having a cleav- age parallel with the base or top, Standard, 1964.

actinic green. An emerald green glass of the type used for poison bottles. Dodd.

actinic rays. Those rays of the spectrum that are the most powerful in producing chem- ical changes; occurring in the blue, violet, and ultraviolet, all of which are contained in sunlight. Standard, 1964.

actinide elements; actinide series; actinides. a. The group of chemical elements of in- creasing atomic number, starting with acti- nium (atomic number 89) and extending through atomic number 103. The names, chemical symbols, and atomic numbers of the members of the series are: actinium, Ac, 89; thorium, Th, 90; protoactinium or protactinium, Pa, 91; uranium, U, 92, neptunium, Np, 93; plutonium, Pu, 94; americium, Am, 95; curium, Cm, 96; berkelium, Bk, 97; californium, Cf, 98; einsteinium, Es, 99; fermium, Fm, 100; mendelevium, Md, 101; and nobelium, No, 102. Element 103, discovered in 1961 and named lawrencium (symbol, Lw), is ex- pected to be the last member of the acti- nide series. CCD 6d, 1961. b. The elements with atomic numbers above 88. According to many authorities, these elements occupy one single place in the extended periodic table, in the same group into which the rare earth elements (lanthanides) are classified. Gaynor. c. Radioactive elements, atomic numbers 89 to 103. Hurlbut.

actinides. See actinide elements.

actinide series. See actinide elements. CCD 6d, 1961.

actinium. A radioactive element found in nature as a constituent of all uranium ores, 1 ton of pure pitchblende contains 0.15 milligram of actinium, Actinium has an atomic number of 89 and is the first mem- ber of the actinide series of elements. The most important source of actinium is pile neutron bombardment of. radium. Except for the sulfides, the compounds of actinium are colorless. Symbol, Ac; mass number of the most stable isotope, 227. CCD 6d, 1961.

actinium A. A name for polonium 215, a member of the actinium disintegration series; symbol, AcA; emits alpha and beta rays; and half-life, .0018 second. NRC- ASA N1.1-1957; Handbook of Chemistry and Physics, 45th ed., 1964, p. B-80.

actinium B. a. A name for lead 211, a mem- ber of the actinium disintegration series. NRC-ASA N1.1-1957. b. A very short- lived radioactive element formed by the degradation of AcA (polonium 215) ; sym- bol, AcB; atomic number, 82; atomic weight, 211; isotopic with RaB (lead 214), RaD (lead 210), ThB (lead 212), and lead; emits beta rays; half-life, 36.1 min- utes; and degrades to AcC (bismuth 211). Hess; Handbook of Chemistry and Physics,

45th ed., 1964, p. B-77.

actinium C. a. A name for bismuth 211, a member of the actinium disintegration series. NRC-ASA N1.1-1957, b. A very short-lived radioactive element formed by the degradation of AcB (lead 211); sym- bol, AcC; atomic number, 83; atomic

actinium C

weight, 211; isotopic with RaC (bismuth 214), RaE (bismuth 210), ThC (bismuth 212), and bismuth; emits alpha and beta rays; half-life, 2.15 minutes; 0.3 percent of it degrades to AcC’ (polonium 211); and 99.7 percent of it degrades to AcC” (thallium 207). Hess; Glasstone, 2, p. 135; Handbook of Chemistry and Physics, 45th ed., 1964, p. B-78.

actinium C’. a. A name for polonium 211, a member of the actinium disintegration series. NRC-ASA NI1.1-1957. b. An ex- tremely short-lived radioactive element formed by the degradation of AcC (bis- muth 211) ; symbol, AcC’; atomic number, 84; atomic weight, 211; isotopic with RaC’? (polonium 214), polonium, AcA (polonium 215), and ThA (polonium 216); emits alpha rays; half-life, 0.52 second; and degrades to Ac] (AcPb, actinium-lead, or lead 207). Hess; Hand- book of Chemistry and Physics, 45th ed., 1964, p. B-80.

actinium C”, a. A name for thallium 207, a

member of the actinium disintegration series. NRC-ASA N1.1-1957. b. A very short-lived radioactive element formed by the degradation of AcC (bismuth 211); symbol, AcC”; atomic number, 81; atomic weight, 207 or 207.16 (thallium 207) ; isotopic with thallium, RaC” (thallium 210), and ThC” (thallium 208); emits beta rays; half-life, 4.78 minutes; and degrades to AcD (AcPb, actinium-lead, or lead 207). Hess; Handbook of Chemistry and Physics, 45th ed., 1964, p. B-75.

actinium D. The final element of the dis-

integration series formed by the spontane- ous degradation of uranium 235 and suc- cessive elements through the actinium dis- integration series, and it is the immediate descendent of AcC’ (polonium 211) and AcC” (thallium 207). It is lead having an atomic weight of about 207 (lead 207) and it undergoes no radioactive change; symbol, AcD, AcPb, or Pb*’. It is an isotope of ordinary lead; and is not radio- active, but infinitesimal quantities of radio- active isotopic elements entangled in the lead give it an apparent radioactivity. Also called actinium-lead (AcPb). Hess; Hand- book of Chemistry and Physics, 45th ed., 1964, p. B-77.

actinium disintegration series; actinium de- cay series; actinium series. a. A disinte- gration series of little known radioactive elements, of which natural actinium is the best known and most stable member. These elements are produced in the radioactive disintegration of uranium 235 (actinou- ranium, AcU) into actinium 227 and of the actinium 227 into lead 207, which is the stable end-product of the disintegration series. CCD 6d, 1961. b. Uranium 235 to thorium 231 to protactinium 231 to actin- ium 227 to thorium 227 plus francium 223 to radium 223 to radon 219 to polo- nium 215 to lead 211 plus astatine 215 to bismuth 211 to polonium 211 plus thallium 207 to lead 207, the stable end- product. Glasstone, 2, p. 135.

actinium emanation. See actinon. Hess.

actinium K. A name for francium 223, a member of the actinium disintegration series; symbol, AcK; emits alpha and beta rays; and half-life, 22 minutes. NRC-ASA N1.1—1957; Handbook of Chemistry and Physics, 45th ed., 1964, p, B-82.

actinium lead. The final residual product of the breaking down of uranium 235 through the actinium series; atomic weight, 207;

an isotope of lead. Hess.

actinium series. See actinium distintegration

series. CCD 6d, 1961.

actinium X. A short-lived radioactive ele-

ment formed by the degradation of RdAc (radioactinium; thorium 227) and of AcK (actinium K ; francium 223) ; symbol, AcX ; atomic number, 88; atomic weight, 223 (radium 223) ; isotopic with radium, meso- thorium I (radium 228; symbol, MsTh:), and thorium X (radium 224; symbol, ThX); emits alpha rays; half-life, 11.7 days; and degrades to actinon (radon 219;

activation analysis

600° F to drive off the moisture. The cycle of adsorption and reactivation can be re- peated many times, Used as a catalyst or 2 catalyst carrier. CCD 6d, 1961.

activated carbon. Carbon, mostly of vege- table origin, and of high adsorptive capac- ity. Used in gas masks and for decolor- izing liquids. Bennett 2d, 1962.

activated charcoal. See activated carbon. Pryor, 3.

activated clay. A clay whose adsorbent char- acter or bleaching action has been en- hanced by treatment with acid. Bentonite

actinium emanation; symbol, An or AcEm). Hess; Handbook of Chemistry and Phy- sics, 45th ed., 1964, p. B-82; Glasstone, 2, palo

actinoform. Having a radiate form. Rice.

actinolite. A natural hydroxy-calcium-mag- nesium-iron silicate Caz(Mg,Fe) :SisOz2 (OH)»2; green color; monoclinic; luster vitreous to silky; fibrous to granular; fibers brittle; Mohs’ hardness, 5.6; specific grav- ity, 2.9 to 3.2. Found in the United States, Canada, and Europe. Used as a minor asbestos mineral and in building material. An amphibole. CCD 6d, 1961.

actinomycetes. Small fungi with character- istics intermediate between the true bac- teria and the molds, and which produce a true mycelium. BuMines I.C. 8075, 1962, p. 63.

actinon; actinium emanation. A_ gaseous, inert, very short-lived radioactive element of the actinium disintegration series and formed by the degradation of AcX (actin- ium X; radium 223); symbol, An or AcEm; atomic number, 86; atomic weight, 219 (radon 219) ; isotopic with radon and thoron (radon 220; symbol, Tn); emits alpha particles; half-life 4.0 seconds; and degrades into AcA (polonium 215). Hess; Handbook of Chemistry and Physics, 45th ed., 1964, p. B-81.

actinote. Synonym for actinolite. Dana 6d, p. 389.

actinouranium; actinium-uranium. An _iso- tope of uranium; uranium 235; symbols, U™ or AcU; atomic number, 92; atomic weight, 235.04; the isotope from which the actinium disintegration series of radioactive elements descends; emits alpha particles; half-life, 7.13 X 10° years; and degrades to uranium Y (thorium 231; symbol, UY). If it is supposed that uranium, like other heavy elements, is formed from stellar matter, it is likely that actinouranium of odd atomic weight would be formed in smaller quantity than the main isotope of even atomic weight. Even, however, if we suppose they were formed in equal quan- tity, it can be shown that it would require only 3.4 X 10° years to bring the quantity down to the 0.28 percent that is observed. Hess; Handbook of Chemistry and Physics, 45th ed., 1964, p. B-86.

actinouranium disintegration series. See actinium disintegration series. NRC-ASA N1.1-1957.

activate. A natural bleaching clay, effective in removing green color from oils. Bennett 2d, 1962.

activated. Chemical reaction being involved. See also chemisorption. Pryor, 3, p. 7.

activated alumina. A highly porous and granular form of aluminum oxide, Al:Os, having preferential adsorptive capacity for moisture from gases, vapors, and some liquids. When saturated, it can be revived or reactivated by the application of heat within the temperature range of 350° to

clay is most frequently treated in this fashion. CCD 6d, 1961.

activated coal ploughs. With a view to ap-

plying the coal plough to seams too hard to be sheared by the normal cutting blade, German mining engineers have developed various types of power-operated cutters. One consists of a series of compressed-air picks mounted above each other; another, of a resonance pattern, houses two high- speed motors eccentrically mounted and rotating in opposite directions. The latter imparts a vibration to the cutting edge equivalent to 2,500 blows per minute with a stroke of 3/16 inch to 1/4 inch and a force of approximately 200 tons. Mason, Ora fe AGG:

activated plough. See Huwood slicer. Nelson. activated sludge. A process of sewage dis-

posal in which air is blown through the sludge to stimulate bacterial action, thereby making complex harmful substances simple and innocuous. Ham.

activated water. The passage of ionizing ra-

diation through water produces, tempo- rarily, ions, atoms, radicals, or molecules in a chemically reactive state. The combined effect of all such entities is said to be due to activated water. Their identity has not been established with certainty, although evidence exists of the presence of free hydroxyl radicals and hydrogen atoms. NRC-ASA N1.1-19357.

activating agent. a. A substance which when

added to a mineral pulp promotes flotation in the presence of a collecting agent. Also called activator. B.S. 3552, 1962. b. Re- agent used particularly in differential min- eral flotation to help cleanse the mineral surface so that a collector may adhere to it and permit or aid its floatability. Fre- quently used to permit floating minerals that had been previously depressed. Mitch- ell, p. 574.

activation. a. The changing of the passive

surface of a metal to a chemically active state. Contrast with passivation. ASM Gloss. b. In the flotation process of ore dressing, the process of altering the surface of specific mineral particles in an ore pulp to promote adherence of certain reagents. Henderson. c. In flotation of minerals, modification of particle surface by atoms, ions, or compounds from aqueous phase, thereby aiding selective sorption of collec- tor agents, for example, CuSO: in flotation of sphalerite. Antonym for depression. See also activation energy; activator; activity. Pryor, 3. d. The process of making a material radioactive by bombardment with neutrons, protons, or other nuclear par- ticles. See also activation analysis; induced radioactivity. L@L.

activation analysis. A method for identify-

ing and measuring the chemical elements in a sample to be analyzed. The sample is first made radioactive by bombardment with neutrons, charged particles, or other

activation analysis

nuclear radiation. The newly radioactive atoms in the sample give off characteristic nuclear radiations that can identify the atoms and indicate their quantity. Activa- tion analysis is frequently more sensitive than chemical analysis. It is being used more and more in research, industry, archeology, crime investigation, and other areas. LOL.

activation energy. The energy required for initiating a physical or chemical transfor- mation, in particular a metallurgical reac- tion; for example, plastic flow, diffusion, or chemical reaction. The activation energy may be calculated from the slope of the line obtained by plotting the natural log of the reaction rate versus the reciprocal of the absolute temperature. ASM Gloss.

activator. a. In flotation, a chemical added to the pulp to increase the floatability of a mineral in a froth, or to refloat a de- pressed (sunk) mineral. Also called ac- tivating reagent. C.T.D. b. A reagent that affects the surface of minerals in such a way that it is easy for the collector atoms to become attached. It has the opposite effect of depressor. Compare depressor. Newton, p. 100 c. A substance which is required in trace quantities to impart luminescence to certain crystals. Silver and copper are activators for zinc sulfide and cadmium sulfide pigments. CCD 6d, 1961. d. Ions which are photon emitters. VV. e. Any agent that causes activation. Ben- nett Td, 1962.

active agents. Surface-active substances which immunize solids against a parting liquid. Hess.

active centers. Areas on the surface of a solid which, by reason of position projecting, or on an edge or corner of the particle, share only a minor part of their electro- static field with the rest of the surface. They thus have excess unabsorbed field available for external attraction, for exam- ple, adsorption and catalysis. Pryor, 3.

active coefficient of earth pressure. The min- imum ratio of the minor principal stress to the major principal stress. Applicable where the soil has yielded sufficiently to develop a lower limiting value of the minor principal stress. ASCE P1826.

active earth pressure. a. The minimum value of earth pressure. This condition exists when a soil mass is permitted to yield sufficiently to cause its internal shear- ing resistance along a potential failure surface to be completely mobilized. ASCE P1826. b. The lateral force or push from the earth mass onto a wall or structure. Nelson.

active earths. Adsorbents, such as charcoal, roasted bauxite, or certain naturally oc- curring silicates, that act as decolorizing agents, or aid in the removal of unsatu- rated compounds, in the refining of oils and fats. Bennett 2d, 1962.

active entry. An entry in which coal is being mined from a portion thereof or from connected sections. I.C. 8001, 1960, p. I.

active fault. One liable to further movement. Compare passive fault. Carson, 2, p. 74.

active glacier. A glacier in which some of the ice is flowing. A.G.I.

active lime. That portion of total lime which undergoes seasonal changes of volume. Foundations are usually taken below the active layer. Nelson. b. A layer of ground above the permafrost which thaws in the summer and freezes again in the winter. Also known as a mollisol. A.G.I.

active lime. That portion of total lime which will react with magnesium chloride in a cement. Bennett 2d, 1962 Add.

active mass. Number of gram-molecular weights in a solution or gas, per liter. Pryor, 3.

active permafrost. Permafrost which, after having been thawed due to natural or artificial causes, is able to return to perma- frost under the present climate. A.G.I.

active state of plastic equilibrium. Plastic equilibrium obtained by an expansion of a mass. ASCE P1826.

active workings. All places in a mine that are ventilated and inspected regularly. U.S. Bureau of Mines Federal Mine Safety Code—Bituminous Coal and Lignite Mines, Pt, I Underground Mines, October 8, 1953.

activity. a. In nuclear physics, the rate of decay of atoms by radioactivity. It is meas- ured in curies. Bennett 2d, 1962 Add. b. The ideal or thermodynamic concentration of a substance, the substitution of which for the true concentration, permits the application of the law of mass action.

Actomag. Selectively calcined dolomite, es- sentially CaCOs and MgO containing some CaCOs; used in fertilizers. Bennett 2d, 1962.

actual age. In geology, the age of a given feature or event expressed in years or cen- turies. This can seldom be ascertained accurately, and most geologic estimates are subject to wide margins of error. Stokes and Varnes, 1955.

actual aggregate breaking strength. The sum total of the actual tensile tests which have been made on wires before manufacture into wire rope. Ham.

actual breaking strength. The breaking load obtained from a tensile test to destruction on a sample of rope. Ham.

actual horsepower. The horsepower really developed, as proved by trial. Standard, 1964.

actual performance curve. A performance curve showing the results actually obtained from a coal preparation treatment. B.S. 3552, 1962.

actual power. See actual horsepower. Stand- ard, 1964.

actuated roller switch. A switch placed in contact with the belt conveyor immediately preceding the conveyor it is desired to control. In the centrifugal sequence control switch a driving pulley bears against the driving belt and as the latter moves the pulley rotates and the governor weights attached to the pulley shaft are flung out and so complete an electrical pilot circuit and thus start the subsidiary belt. Nelson.

actuator. A device for producing a remotely controlled movement (normally rectilinear) by mechanical means. NCB.

acumulacion. Sp. Accumulation, oil pool. Hess.

acute bisectrix. The line which bisects the acute angle of the optic axes of biaxial minerals. Fay.

acute exposure (to radiation). Exposure to irradiation for a short period of time. NCB.

acyclic. Arranged in spirals, not in whorls. A.G.I.

aczolling. The treatment of timber with a mixture of metallic ammoniates and an antiseptic acid (derivative of phenol or naphthalene). Liddell 2d, p. 493.

adamant. An imaginary stone of impene- trable hardness; formerly used of the dia- mond and other substances of extreme

adaptive convergence

hardness. Webster 3d.

adamantine. a. Diamond hard. A commer- cial name for chilled steel shot used in the adamantine drill, which is a core barrel type of rock-cutting drill with a cutting edge fed by these shots. Pryor, 3. b. Like the diamond in luster. Webster 3d.

adamantine drill; shot drill. A core drill em- ployed in rotary drilling in very hard ground. A steel-cylinder bit with a diagonal slot cut in the lower edge is attached to a core barrel and a small quantity of chilled steel shot fed in with the water at intervals. These find their way beneath the bit and wear away the rock as the bit rotates. A core from 4 to 30 inches in diameter is obtained. Fay.

astamenting luster. Diamondlike luster. Hurl-

ut.

adamantine shot. Synonym for shot. See also shot, h, Long.

adamantine spar. A name for silky brown corundum, Now more generally applied to dull opaque corundum from India, ground for use as a polishing agent. Same as seal sapphire. Shipley.

adamellite. Quartz monzonite. A.G_I.

adamic earth. a. Eng. A kind of red clay. Fay. b. A name some have given to com- mon clay. Arkell.

adamite. A rare hydrous zinc arsenate, Znz AssOsAn(OH):s, occurring granular or in crusts and crystallizing in the orthorhombic system. Fay. Weakly radioactive; variable color: yellowish, greenish, or violet, rarely colorless or white; found in the oxidized zone of zinc ore bodies. Associated with smithsonite, calcite, malachite, hemimor- phite, limonite, and azurite. Small amounts of uranium have been found in some specimens of adamite. Crosby, p. 117.

Adams chromatic value system. A method for the quantitative designation of color in terms of (1) lightness, (2) amount of red or green, and (3) amount of yellow or blue. The system has been used in the examination of ceramic colors, Dodd.

adamsite. A greenish-black muscovite found in a schist at Derby, Vt.; has been called margarodite. Dana 6d, pp. 614, 616.

Adams process. A method for the removal of iron compounds from glass-making sands by washing with a warm solution of acid Na (sodium) oxalate containing a small quantity of FeSQ.:. Dodd.

Adam’s snuffboxes. Eng. Hollow, roughly rectangular pebbles lined with goethite, Lenham beds, Netley Heath, Surrey. Com- pare snuffboxes. Arkell.

Adams-Williamson annealing schedule. A procedure, derived from first principles, for determining the optimum annealing con- ditions for a particular glass. Dodd.

ada mud. A conditioning material which may be added to drilling mud in order to obtain satisfactory cores and samples of formations. Williams.

adapter; adapter flange. A form of flange used to mount wheels in which the holes are larger than the machine arbors. See also safety flange. ACSG, 1963.

adapter brick. Special arch-wedge key brick, used for permitting the use of straight brick in a roughly dome-shaped construction. Bureau of Mines Staff.

adapter flange. See adapter.

adapter trough. A short section of a shaker conveyor trough that serves as a connect- ing link between any two sizes of trough. Jones.

adaptive convergence. Synonym for conver-

adaptive convergence

gent evolution. A.G.J.

adaptive metallurgy. Branch of metallurgy that deals with use of metals and alloys. Bennett 2d, 1962 Add.

adarce. A calcareous sediment of some min- eral springs. Standard, 1964.

A.D.C. test. See sensitivity to propagation. McAdam II, p. 19-20.

added diamonds. As used by the diamond- bit manufacturing industry, the number or carat weight of new diamonds that must be added to the resettable diamonds sal- vaged from a worn bit in order to have enough to set a new bit. Long.

addendum. The point or portion of the tooth of a gearwheel lying outside the pitch circle. Crispin.

addendum circle. The outer circumference of a gearwheel. Crispin.

additional agent. A substance added to a solution for the purpose of altering or controlling a process, Examples: wetting agents in acid pickles; brighteners or anti- pit agents in plating solutions; and inhibi- tors. ASM Gloss.

additional element. Any element added in relatively small quantity to an alloy for scavenging or modifying its properties. Bennett 2d, 1962.

additive. A correction applied to times of seismic reflections measured from an arbi- trary time origin. The additive is normally applied for the purpose of translating the time origin to correspond to the datum elevation chosen for computation, and it is algebraic in sign. A.G.J.

additive constant. The Icngth which must be added to the product.of the intercept, on the staff in stadia work and the multiplying constant, to give the true distance from the center of the telescope to the staff. The length is often less than 1 foot. Ham.

addle; adle. N. of Eng. To earn by labor. Fay.

addling. N. of Eng. The act of earning of labor. Fay.

addlings. A term used in the northern and parts of other coalfields in Great Britain to describe earnings or wages. Nelson.

adductor muscle. A muscle passing across from one valve of a bivalve to the other, for the purpose of closing the shell. Shipley.

Adelaide ruby. Blood-red pyrope from South Africa. Hess.

Adeline steelmaking process. A process of producing precision castings of steel or steel alloys, which comprises first forming the steel or steel alloy in molten form by the aluminothermic process, by igniting a mixture of iron ore and aluminum, then running the molten metal into a mold pre- pared by packing a refractory mold com- position round a model made of wax or other comparatively low melting point sub- stance and heating to melt out the wax and consolidate the mold, and _ finally centrifuging the mold. Osborne.

adelite. A gray, basic hydrous arsenate of calcium and magnesium, 2CaO.2MgO.Asz2 O;.H2O; 48.5 to 50.0 percent AssOs; Mohs’ hardness, 5; specific gravity, 3.71 to 3.76; probably a deep-seated tactite mineral. Hess.

ader wax. Crude ozocerite in leafy masses. Fay.

adherence. a. The degree of adhesion of a porcelain enamel or other ceramic coating to the metal substrate. ASTM C286-65. b. In magnetic testing, the property of a powder, either dry or in liquid suspension, which depends upon its magnetic perme-

ability and causes it to accumulate in a well-defined area above a crack or other defect. Rolfe.

adherence failure. Insufficient adherence to

metal to hold the coating. Visually indi- cated by bright metal in a fractured area. Bryant.

adhesion. a. Holding surfaces together with

an adhesive. See also adhesive. CCD 6d, 1961. b. The sticking of two surfaces together due to molecular attraction for each other. CCD 6d, 1961. c. Shearing resistance between soil and another mate- rial under zero externally applied pressure. ASCE P1826. d. Force of attraction be- tween the molecules (or atoms) of two different phases, such as liquid brazing filler metal and solid copper, or plated metal and basis metal. Compare cohesion. ASM Gloss. e. The attraction of the mole- cules in the walls of interstices for mole- cules of water. A.G.I. f. The soil quality of sticking to buckets, blades, and other parts of excavators. Nichols. g. In the flotation process, clinging of a particle to air-water interphase or to a bubble. Fundamentally, adhesion is the force between two unlike substances, for example, water and glass. In the concentration of diamonds from blue ground, the gems adhere strongly to a greased plane surface. Adhesion is due to molecular attraction at an interface. Pryor, 3. h. The coefficient of adhesion or static friction between the wheels of the locomotive and the rails, upon which the pulling power or tractive effort of the locomotive depends, is a function of the material of the wheel tires and the rails, the condition of the rails, whether wet, dry, or sanded, and to some extent on the springing and center of gravity of the locomotive. Sinclair, V, p. 218.

adhesion tension. Energy of attraction across an interface. Pryor, 3.

adhesion-type ceramic veneer. Ceramic slabs approximately 11% thick, held in place by the adhesion of the mortar to the ceramic veneer and the backing wall. No metal anchors are required. See also ceramic veneer. ACSG.

adhesive. A substance capable of holding materials together by surface attachment. CCD 6d, 1961.

adhesive force. The frictional grip between

two surfaces in contact, for example, be- tween the driving wheel of a locomotive and the rail; the product of the weight on the wheel and the friction coefficient between the wheel and rail. Nelson.

adhesive slate. A very absorbent slate that adheres to the tongue if touched by it. Standard, 1964.

adiabatic. A change at constant total heat. An action or a process during which no heat is added or subtracted. Strock, 10.

adiabatic calorimeter. A calorimeter which theoretically remains unaffected by its sur- roundings, and neither gains nor loses heat. The sample under investigation (solid or powder) is enclosed in a tapered copper container along the central axis of which is a heating element. The sample and its container are completely enclosed by a copper radiation jacket which is main- tained at the same temperature as the sample by electric heaters; the radiation jacket is, in turn, enclosed in a furnace. The furnace is evacuated or filled with inert gas, as desired. The temperature of the sample and jacket are measured with platinum/platinum—10 percent rhodium

adit

thermocouples, and the temperature dif- ference between the sample and the radia- tion jacket is indicated by copper/gold palladium alloy thermocouples (the sample container and the radiation jacket act as return leads). Osborne.

adiabatic compression. Compression in which no heat is added to or subtracted from the air and the internal energy of the air is increased by an amount equivalent to the external work done on the air. The in- crease in temperature of the air during adiabatic compression tends to increase the pressure on account of the decrease in volume alone; therefore the pressure during adiabatic compression rises faster than the volume diminishes. Lewis, pp. 665-666.

adiabatic efficiency. This is obtained by di- viding the power, theoretically necessary to compress the air and deliver it without loss of heat, by the power supplied to the fan shaft. Roberts, I, p. 186.

adiabatic expansion. Expansion in which no heat is added to or subtracted from the air, which cools during the expansion be- cause of the work done by the air. Lewis, p. 665.

adiabatic phenomena. Those which occur without a gain or loss of heat. Hy.

adiabatic reaction. A reaction which takes place without transfer of heat to or from the body concerned. Hess.

adiabatic temperature. Theoretical maximum temperature. This means the temperature that would be attained if no heat were lost to the surroundings. Newton, p. 135.

adiabatic temperature changes. The com- pression of a fluid without gain or loss to the surroundings is work performed on the system and produces a rise of temperature. In very deep water such a rise of temper- ature occurs and must be considered in the vertical temperature distribution. Hy.

adiagnostic. Proposed by Zirkel and applied to mineral constituents of a rock that can- not be distinguished even with the aid of a microscope. Johannsen, v. 1, 2d, 1939, p. 164,

adinole. A dense, felsitic, contact-metamor- phic rock composed chiefly of exceedingly fine-grained quartz and albite; the soda may reach 10 percent; actinolite and other min- erals are in smaller quantity. Adinoles are formed by reactions following the intrusion of diabase into shale or slate (Compare spilosite; desmite). They also make up beds in metamorphic rocks (Compare por- phyroid; halleflinta). Hess.

adion. A labile ion, adsorbed sufficiently to be held at a surface, yet free to move on that surface. Pryor, 3.

adipite. An aluminosilicate of calcium, mag- nesium, and potassium having the compo- sition of chabazite. Dana 6d, p. 591.

adipocerite; adipocire. Synonym for hatchet- tite. Fay.

A-dipping. Scot. Toward the dip. Fay.

adit. a. A horizontal or nearly horizontal passage driven from the surface for the working or unwatering of a mine. If driven through the hill or mountain to the surface on the opposite side it would be a tunnel. Lewis, p. 21. Also called drift; adit level. b. As used in the Colorado statutes it may apply to a cut either open or undercover, or open in part and undercover in part, dependent on the nature of the ground. Fay. c. A passage driven into a mine from the side of a hill. Statistical Research Bu- reau.

adit end

adit end. The furthermost end or part of an adit from its beginning, or the very place where the miners are working underground towards the mine. Hess.

adit level. Mine workings on a level with an adit. See also adit. Hess.

adjacent. As generally defined and under- stood, means by, or near, and close, but not actually touching; nonadjacent, represent- ing the opposite situation, means not near, and not close. Ricketts, I.

adjacent sea. Semienclosed sea adjacent to and connected with the oceans. The North Polar, Mediterranean, and Caribbean Seas are examples, Synonym for marginal sea. A.G.I.

adjoining. To be in contact; to lie next to. Jones.

adjustable bed. Bed of a press designed so that the die space height can be varied conveniently. ASM Gloss.

adjustable pipe tongs. Synonym for brown tongs. Long.

adjusting screw. An accurately machined screw on a surveying instrument with which final adjustments are made for leveling, focusing, or setting the instrument in the correct position. Ham.

adjustment. When a number of survey ob- servations are inconsistent, an adjustment is made in order to make each observation consistent with the others. For example, if the three angles of a triangle do not add up to 180°, but to 180°6’, then 2 minutes of arc must be deducted from each angle. Also refers to the operations carried out on the various components of a surveying in- strument so that it will give accurate read- ings. Ham.

adjustment of error. Method of distributing the revealed irregularities over a series of results. Pryor, 3, p. 160.

adjutage; ajutage. Nozzle or tube from which hydraulic water is discharged. Pryor, 3.

adlings. See addlings. Fay.

admiralty brass. Alpha brass in which some of the zinc is replaced by tin to increase strength and corrosion resistance. Com- posed of 70 percent copper, 29 percent zinc, and 1 percent tin. C.T.D.

admiralty coal. A good quality smokeless steam coal as used in the fleet. Tomkeieff, 1954.

admittance; admission. a. Substitution in a crystal lattice of a trace element for a common element of higher valence, for example, lithium cations for magnesium cations. A.G.I. b. Substitution of a com- mon element by a trace element with a higher valence. Schieferdecker.

admixture. a. Applied by Udden to one of the lesser or subordinate of several size grades of a sediment. A.G.I. b. A material (other than coarse or fine aggregate, ce- ment or water) which is added in small quantities during the mixing of concrete, so as to produce some desired modification in one or more of its properties. Also called additive. Taylor.

admixture, coarse. Material coarser than that found in the maximum histogram class in the graphic representation of particle size analysis. A.G.I.

admixture, distant. The two classes at the extreme ends of a histogram representing the particle size analysis of a sediment. A.G.I.

admixture, fine. A material finer than that found in the maximum histogram class in the graphic representation of particle size analysis. A.G.I.

admixture, proximate. The two histogram classes adjacent to the maximum class in the graphic representation of particle size analysis. A.G.I.

admixtures. Materials added to mortar as water-repellent or coloring agents or to retard or speedup setting. ACSG.

adobe. a. Applied to clayey and silty deposits found in the desert basins of the south- western United States and in Mexico where the material is extensively used for making sun-dried brick. The composition is a mixture of clay and silt together with other materials. Most adobes are calcar- eous. Similar deposits are found in other desert basins. The agent of deposition seems to have been mainly water and the places of deposition are more or less flat areas in the central and lower parts of desert basins. The materials, in part at least, have been produced from the rocks of the desert slopes through both decom- position and disintegration. A.G.J. b. The mixed earth or clay of which such bricks are made. Standard, 1964. c. In mining, a brick of pulverized ore mixed with clay, as in quicksilver metallurgy. Fay. d. Syn- onym for mudcap. Long. e. A firm sticky clay. Long.

adobe brick. A large clay brick, of varying size, roughly molded and sun-dried. ACSG.

adobe flat. A broad flat formed by deposition from sheetfloods and floored with sandy clay or adobe. The surface, when dry, is normally hard, smooth, and somewhat streaked in appearance due to the presence of fine crenulations in the direction of flow. USGS Bull. 730, 1923, pp. 69-70.

adobera. A mold for making adobe brick. Hess.

adoberia. An adobe kiln or yard. Hess.

adobe shot. Ordinarily referred to as a dobe shot. A stick or part of a stick of dynamite is laid on the rock to be broken and cov- ered with mud to add to the force of the explosion. A mudcap shot. Hess.

adolescent river. In physical geology, a river in the stage where it has acquired a well- cut channel, sometimes reaching baselevel at its mouth, and a graded bed. Standard, 1964.

A drill rod. A former standard diamond-drill rod superseded in 1954 by the DCDMA standard AW drill rod. Long.

adsorb. To condense and to hold a gas on the surface of a solid, particularly metals. Also to hold a mineral particle within a liquid interface. Fay.

adsorbate. That which is adsorbed by an ad- sorbing substance, or an adsorbent. Pryor, 3.

adsorbed water. a. Water in a soil mass that is held by physicochemical forces, having physical properties substantially different from absorbed water or chemically com- bined water, at the same temperature and pressure. ASCE P1826. b. Water usually one or more molecules thick on a surface held by molecular forces. ACSG, 1963.

adsorbent. A substance which has the ability of condensing or holding other substances on its surface. Active carbon, activated alumina, and silica gel are examples. CCD 6d, 1961.

adsorption. a. A taking up by physical or chemical forces of the molecules of gases, of dissolved substances, or of liquids by the surfaces of solids or liquids with which they are in contact. Webster 3d. b. Physical adhesion of molecules to the surfaces of solids without chemical reaction. ASTM STP No, 148-D. c. A term used in the

advance gates

flotation process. Bureau of Mines Staff. d. The property possessed by some sub- stances, notably those of a carbonaceous nature, by virtue of which they are able to compress and hold on their surface rela- tively large quantities of gas. Very large quantities of firedamp may be released dur- ing the working of a coal seam, and it is apparent that this gas has been stored in coal and its associated strata throughout the ages. Roberts, I, pp. 66-67. e. Broadly, adsorption at a solid-liquid interphase may be physical, electrochemical or chemical. With physical adsorption there is low en- ergy, rapid reversibility and nonspecificity (for example, adsorption of soaps on par- affin-wax). With chemical adsorption high energies, irreversibility and specific action is characteristic. Ionic adsorption includes common-ion adsorption to the mineral lat- tice, and ion exchange between the surface lattice charges of solid and the ions in solution (the surface-modifying effects uti- lized in the flotation process). In physical adsorption there is capture by the solid or adsorbent at its surface of the adsorbate, and alteration in concentration at an inter- face, which may be positive or negative. Pryor, 3. {. Silica gel is an adsorber used in dehumidifying, whereas activated car- bon is an adsorber used to remove odors from air. During adsorption the adsorber undergoes no permanent physical or chemi- cal change. Strock, 10. See also clay ad- sorption, anion; clay adsorption, cation.

adsorption analysis. Separation by differen- tial adsorption. Pryor, c, p. 20.

adsorption isotherm. Relation between quan- tity adsorbed and that not adsorbed at constant temperature. Pryor, 3.

adsorption surface area. Surface area of a particle calculated from data obtained from a stated adsorption method of measure- ment. Pryor, 3.

adularescence. a. A milky white to bluish sheen in gem stones. C.M.D.b. The change- able white to pale bluish luster of an adu- laria cut cabochon. Webster 3d.

adularia; adular. A pure or nearly pure potassium-aluminum silicate, KA1Sis0s; a variety of orthoclase. Fay.

adularia moonstone. Precious See also adularia. Shipley.

adularization. The introduction of or re- placement by adularia, as in the potash spilites (poenites) of Timor. A.G.I.

advance. a. The work of excavating as min- ing goes forward in an entry and in driv- ing rooms; to extract all or part of an area; first mining as distinguished from retreat. B.C.J. b. S. Afr. Term used to denote the progress of a drive or shaft. Beerman. c. To deepen a borehole. Long. d. Rate at which a drill bit penetrates a rock formation. Long. e. Feet drilled in any specific unit of time. Long. f. The linear distance (in feet or meters) driven during a certain time in tunneling, drift- ing, or in raising or sinking a shaft. Fraenkel.

advance development. S. Afr. Development to provide an ore reserve in advance of mining operations. Beerman.

advanced gallery. A small heading driven in advance of the main tunnel in tunnel ex- cavation. Fay,

advance gates. Gate roads that are driven simultaneously with the longwall coal face but which are maintained some 10, 20, or more yards in advance of the face. The area immediately ahead of the coal face

moonstone.

advance gates

is therefore preexplored and steps can be taken to cope with minor disturbances and thus prevent a serious loss of output. See also exploring heading. Nelson.

advance (of a beach). a. A continuing sea- ward movement of the shoreline. A.G.I. b. A net seaward movement of the shore- line over a specified time. Also called pro- gression. A.G.J. c. (Of a glacier) the for- ward movement of a glacier front. A.G.I.

advance overburden. Overburden in excess of the average overburden to ore ratio that must be removed in opencut mining. Institution of Mining, and Metallurgy, Symposium on Opencast Mining, Quarry- ing, and Alluvial Mining, London, 16-19 November 1964, Paper 14, pp. 19-20.

advance per round. The length, measured along the longitudinal axis of the working, tunnel, or gallery, of the hollow space broken out by each round of shots. For raises, it is upward advance; for sunk shafts, downward advance. Fraenkel.

advance stope. A stope in which sections of the face or some pillars are a little in ad- vance of the others. This is achieved either by beginning the stoping of the section which is to be advanced earlier, or by pro- ceeding more quickly. Stoces, v. 1, p. 249.

advance stripping. The removal of barren or subore-grade earthy or rock materials re- quired to expose and permit the minable grade of ore to be mined. The removal of these nonore materials is known as strip- ping. Bureau of Mines Staff.

advance wave. The air pressure wave pre- ceding the flame in a coal-dust explosion. The bringing of the dust into suspension is accomplished by such a wave and the violent eddies resulting therefrom. Rice, George S.

advance working. Mine working that is being advanced into the solid, and from which no pillar is being removed. Fay. See also first working. Kentucky, p. 332.

advancing. Mining from the shaft out toward the boundary. Stoces, v. 1, p. 209. See also working out.

advancing longwall. a. Mining the coal out- ward from the shaft pillar and maintain- ing roadways through the worked-out portion of the mine. Fay, p. 407. b. See longwall advancing.

adventive cone. A subsidiary volcanic cone, usually a cinder cone, on the flank of a larger volcano. Synonymous with parasitic cone; lateral cone. A.G.I.

adventive crater. A volcanic crater on the flank of a large volcanic cone. Fay.

adventure. Corn. A mining enterprise. Fay.

adventurers. Eng. Shareholders or partners in a mining enterprise; in Cornwall, cost book partners. Fay.

adverse. To oppose the granting of a patent to a mining claim. Fay.

adverse claim. A claim made to prevent the patenting of part of the ground within the area in question; for example, an adverse claim is made by a senior locator to exclude the part of his claim that is overlapped by the claim of a junior locator, when the junior locator is applying for patent. Lewis, p. 31.

adverse intent. The terms claim of right, claim of title, and claim of ownership, when used in the books to express adverse intent, mean nothing more than the inten- tion of the dissessor to appropriate and use the land as his own to the exclusion of all others, irrespective of any semblance or shadow of actual title. Ricketts, I.

advertised out. A term used to express the result of the action of a joint owner of a mining claim who by proper notices causes the interest of his coowner to be forfeited for failure to perform his share of the assessment work. Fay.

advp Abbreviation for avoirdupois. BuMin Style Guide, p. 58.

adz. A cutting tool with the blade set at right angles to the handle; used for rough dressing timber. Crispin. Also spelled adze. Webster 3d.

adz-eye hammer. Usually the claw-type nail hammer in which the eye is extended to give a longer bearing on the handle than is the case with other hammers. Crispin.

AEC Abbreviation for Atomic Energy Com- mission. GPO Style Manual, p. 155.

aedelforsite; edelforsite. A name given to a mixture of wollastonite, quartz, and feld- spar from Edelfors, Sweden; to impure wollastonite from Gjellebak, Sweden (called also gillebackit) ; and to impure laumontite, under the impression that they were new minerals. Hess.

aedelite; edelite. Prehnite; 2CaO.Al:O3.3Si- Oz.H2O. Hess.

Aegerite. Trade name for a bitumen allied to wurtzilite. Tomkeieff, 1954. Not to be confused with the pyroxenic mineral aegi- rine. English.

aergirine; aegirite. A scodium-ferric iron sili- cate, NaFe’’(SizOs), occurring commonly in soda-rich igneous rocks; monoclinic; Mohs’ hardness, 6 to 6.5; specific gravity, 3.40 to 3.55. Dana 17. Synonym for ac- mite. See also pyroxene. A.G.I.

aegirine-augite. Intermediate between augite and aegirite. Same as aegirite-augite. Eng- lish.

aegirite. See aegirine for pyroxene mineral; Aegerite for trade name of bitumen.

aenigmatite. A rare titanium-bearing silicate, (Na, Ca), (Fe*, Fe**, Mn, Ti, Al) is (SizO;)«; triclinic; black color; found associated with alkalic rocks. Dana 17, pp. 413, 597.

aeolian. Synonym for eolian. Obsolete. A.G.J.

aeolotropic; eolotropic. Possessing different properties in different directions ; especially, not equally elastic, or not conducting heat, light, etc. equally in all directions. Stand- ard, 1964. Synonym for anisotropic. Oppo- site of isotropic.

Aeonite. Trade name for a bitumen allied to wurtzilite. Tomkeief, 1954. Similar to elaterite. English.

aerate. a. To expose to the action of the air; to supply or to charge with air. Standard, 1964. b. To expose to air by passing air through; to aerify; to cause air to bubble through. Webster 3d. c. To introduce air into (a liquid) by stirring, spraying, or some similar method. Webster 3d. d. To supply or to impregnate with air (as soil or sand). Webster 3d. e. To charge with carbon dioxide or other gas, as soda water. Standard, 1964.

aerated concrete. Concrete with a high pro- portion of air spaces resulting from a foaming process; the bulk density may vary from about 35 to 90 pounds per cubic foot. Aerated concrete is chiefly used for making precast building units. It is also known as gas concrete, cellular concrete, or foamed concrete. Dodd.

aeration. a. The introduction of air into the pulp in a flotation cell in order to form air bubbles. B.S. 3552, 1962. b. In min- eral dressing use of copious air bubbled into mineral pulps, (1) to provide oxygen in cyanidation; (2) to prevent settlement

aerial magnetometer

of solids; and (3) to remove aerophilic minerals in froth flotation by binding them into a mineralized froth which is tempo- rarily stabilized by frothing agents. Pryor, 3. c. The process of relieving the effects of cavitation by admitting air to the sec- tion affected. Seelye, 1. d. The process of mixing air or other gases with water, sew- age, etc. Seelye, 1.

aeration cell. An elecrtolytic cell, the electro- motive force of which is due to a differ- ence in air (oxygen) concentration at one electrode as compared with that at another electrode of the same material. Also called oxygen cell. Osborne.

aeriation of cement. The effect of the atmos- phere on Portland cement during storage. Dry air has no effect, but if it is exposed to moist air both moisture and carbon di- oxide are absorbed with erratic effects on the setting behavior. See also air entrain- ing. Dodd.

aeration, zone of. The zone in which the interstices of the functional permeable rocks are not (except temporarily) filled with water under hydrostatic pressure; the in- terstices are either not filled with water or are filled with water that is held by capil- larity. Rice.

aerator. a. An apparatus for charging water with gas under pressure, especially with carbon dioxide. Standard, 1964. b. Any contrivance for supplying a stream of air or gas, as for fumigating, destroying fungi, insects,etc. Standard, 1964.

Aerencheon apparatus. A liquid-air type of breathing apparatus which is smaller and lighter than the Aerophor apparatus. The entire apparatus is carried on the wearer’s back and has a weight of only 32 pounds, which is 8 pounds lighter than the Aero- phor breathing apparatus. The mouthpiece of the Aerencheon apparatus has been spe- cially designed to prevent the involuntary inhalation of the outside atmosphere should the lip muscles become slack. McAdam, pp. 42-44,

Aerex fan. Trade name for an axial-flow type of mine fan. It has the advantages of high efficiency, small size, and high oper- ating speeds. See also fan, a. Nelson.

aerial. Relating to the air or atmosphere. Subaerial is applied to phenomena occur- ring under the atmosphere as subaqueous is applied to phenomena occurring under- water. Fay.

aerial arch. An anticline, the crest of which has been eroded away. Hess.

aerial cableway. An arrangement of over- head cable supporting a traveling carriage from which is suspended a skip or con- tainer which can be lowered and raised at any desired point. Nelson.

aerial geophysical prospecting. Geophysical prospecting from an aircraft, which may be a combined aeromagnetic, electromagnetic, and radiometric survey. An airborne mag- netometer survey is conducted so that the area is covered systematically, by flying along equally spaced profile lines across the area. In mineral prospecting, the air- craft is maintained at a constant height above the ground, known as profile flying. Among the mineral deposits that may be identified by a magnetometer are magnet- ite, ilmenite, pyrrhotite, and oil. See also aerial mapping; electromagnetic detector. Nelson. Radiometric instruments are used to detect radioactive minerals. Bureau of Mines Staff.

aerial magnetometer. A device used to meas-

aerial magnetometer

ure variations in the earth’s magnetic field while being transported by an_ aircraft. Same as airborne magnetometer. A.G.I.

aerial mapping. The taking of continuous vertical photographs from an airplane for geophysical and other purposes. One such method employs a vertically mounted 35- millimeter positioning camera, which pho- tographs continuously the track of the air- craft. From the prints obtained, a mosaic map is constructed. The map is closely examined through double-eyepiece viewers, etc., and the possible nature of the geology and subsurface structure can be inferred by trained geologists. See also profile fly- ing; radioaltimeter. Nelson.

aerial railroad. A system of wires from which to suspend cars or baskets, as in hoisting ore. Standard, 1964. See also aerial tram- way. Fay.

aerial ropeway. System of ore transport used in rough or mountainous country. A cable is carried on pylons, and loaded buckets are (1) towed from loading point to dis- charge; (2) suspended from a carriage running on this cable, and then returned empty along a second cable; or (3) the whole cable moves continuously carrying buckets which hang from saddle clips and are loaded and discharged automatically or by hand control. Pryor, 3. See also bicable; jig-back; monocable; aerial tram- way. Sinclair, V, pp. 359-361.

aerial spud. A cable for moving and anchor- ing a dredge. Fay.

aerial tramway. A system for the transporta- tion of material, as ore or rock, in buckets suspended from pulleys or grooved wheels that run on a cable, usually stationary. A moving or traction rope is attached to the buckets and may be operated by either gravity or other power, as determined by topographic features or other conditions. Fay. An aerial tramway transports loads in carriers suspended from wire ropes forming the tracks, between fixed points, usually a long distance apart. Tramways are divided into three classes: (1) bicable, (2) twin- cable, and (3) monocable. Peele, v. 2, sec. 26, p. 2.

aerify. a. To infuse or to force air into; to aerate. See also aerate. a. Webster 3d. b. To change into an aeriform state; to va- porize. Webster 3d. c. To change into a gaseous form. Standard, 1964.

arites. Metallites; a word proposed to cover all ores and metalliferous matter. Hess.

aerobe. An organism that lives in the pres- ence of free oxygen. The oxygen is usually used in the cell’s metabolism. I.C. 8075, 1962, p. 63.

aeroclay. Clay, particularly china clay, that has been dried and air separated to re- move any coarse paritcles. Dodd.

aerocrete. A patented, porous, lightweight concrete. Bennett 2d, 1962.

aerodynamical efficiency. This furnishes a measure of the capacity of a fan to pro- duce useful depression (or positive pressure in the case of a forcing fan) and indicates the extent to which the total pressure pro- duced by the fan is absorbed within the fan itself. Sinclair, I, p. 169.

aerodynamic fan, backward-bladed. A fan that consists of several streamlined blades mounted in a revolving casing. The cross section and spacing of the blades is de- signed aerodynamically. This design insures that the air flows between the blades and leaves the rotor in a steady and regularly distributed stream. This appreciably re-

duces frictional, conversion, and recircula- tion losses. Fans of a convenient size can handle large volumes of air at the highest pressures likely to be required in mine ventilation. Roberts, I, p. 184.

aerodynamic instability. Flutter which may occur in a structure exposed to wind force. This form of instability can be guarded against by suitable design. Ham.

aeroembolism. a. The formation or liberation of gases in the blood vessels of the body, as brought on by a change from a high, or relatively high, atmospheric pressure to a lower one. H&G. b. The disease or con- dition caused by the formation or libera- tion of gases in the body. The disease is characterized principally by neuralgic pains, cramps, and swelling, and sometimes re- sults in death, Also known as decompres- sion sickness. H&G,

aerofall mil. A short, cylindrical grinding mill with a large diameter used dry, with either coarse lumps of ore, pebbles, or steel balls as crushing bodies. The mill load is airswept to remove finish mesh material. Pryor, 3.

aeroflocs. Synthetic water-soluble polymers used as flocculating agents. Bennett 2d, 1962 Add.

aerofoil. A body shaped so as to produce an aerodynamic reaction (lift) normal to its direction of motion, for a small resistance (drag) in that plane. A wing, plane, aile- ron, rudder, elevator, etc. C.T.D.

aerofoil-vane fan. An improved centrifugal- type mine fan. The vanes, of aerofoil sec- tion, are curved backwards from the di- rection of rotation. This fan is popular in British coal mines and total efficiencies of about 90 percent have been obtained. See also fan, a. Nelson.

Aerofroth Frothers. Trademark for a group of surface-active agents. Used primarily as foaming agents or frothers in flotation processing of ores and minerals. CCD 6d, 1961.

aerograph. A device for spraying powdered glaze or color on the surface of pottery by means of compressed air. Dodd.

aerohydrous. a. Enclosing a liquid in the pores or Cavities, as some minerals. Stand- ard, 1964. b. Characterized by the pres- ence of both air and water. Standard, 1964.

aeroides. A name for pale sky-blue aqua- marine. Shipley.

aerolite. a. A stony meteorite in which sili- cates predominate over metallic iron, Syn- onym for meteoric stone; sporadosiderite. Schieferdecker. b. A type of meteorite con- sisting largely of silicates. A.G.J. c. An alloy of 91.93 percent aluminum, 0.12 percent zinc, 0.45 percent silicon, 0.97 percent iron, 1.15 percent copper, and 0.38 percent manganese; specific gravity, 2.74. Urea-formaldehyde cement. Bennett 2d, 1962.

aeromagnetic prospecting. A technique of ex- ploration of an area using an aerial mag- netometer to survey that area. A.G.I.

aerometer. An instrument for ascertaining the weight or the density of air or other gases. Webster 3d.

Aeromine Promoters. Trademark for a group of cationic flotation reagents. Used in froth flotation of ores and minerals, primarily silica and silicates. CCD 6d, 1961.

aerophore. a. A respirator in the form of a tank which receives the exhalations from the lungs, and containing chemicals de- signed to revive the air to render the air

A-frame headgear

fit for breathing. Fay. b. A portable ap- paratus containing a supply of compressed air for respiration, as for a miner. Webster

aerosiderite. An obsolete term for siderite. A.G.I. aerosiderolite. An obsolete term for sidero-

lite. A.G.I,

aerosite. Same as pyragyrite. Standard, 1964.

aerosol. A suspension of ultramicroscopic

solid or liquid particles in air or gas, as smoke, fog, or mist. Webster 3d.

Aerosol. Trade name of strong wetting agent based on sulfonated bi-carboxy-acid esters. Pryor, 3.

aerosphere. The atmosphere considered as a spherical shell of gases surrounding the earth. Standard, 1964.

aerugite. A grass-green to brown nickel ar- senate, perhaps 5NiO.As2O;; an analysis gave 48.77 percent nickel. It is an oxidized vein mineral, Hess.

aerugo. a. Copper rust; verdigris; especially, green copper rust adhering to old bronzes. Standard, 1964. b. Copper carbonate, due to weathering of the metal; especially, the patina adhering to old bronzes. Hess.

aeschynite. A black to transparent yellowish- brown, complex orthorhombic titanocolum- bate of thorium and the cerium metals with some iron, calcium, etc.; 32 to 57 percent, Cb2O;; 21 to 42 percent, TiOz; 19 to 24 percent, cerium earths; 1 to 3 percent, (Y,Er)2Os; Mohs’ hardness, 5-6; specific gravity, 4.93-5.17; in pegmatites. Hess.

aethiops mineral. Metacinnabarite, a black isometric HgS. Dana 64d, p. 63.

aetite. a. A nodule consisting of a hard shell of hydrated oxide of iron within which the yellow oxide becomes progressively softer toward the center which is sometimes empty. Fay. b. Synonym for eaglestone. Standard, 1964,

AFA rammer. Apparatus designed by the American Foundrymen’s Association for the preparation of test pieces of foundry sand; it has also been applied as a method for the preparation of test pieces of partic- ulate refractory materials. The rammer operates by a 14-pound weight falling through a height of 2 inches on the plunger of a 2-inch diameter mold; normally, the weight is allowed to fall on the mold three times. Dodd.

affinity. In ion exchange, relative strength of attachment of competing ions for an- chorage on a resin. Pryor, 3,

affluent. A tributary stream. Standard, 1964.

Afghanistan lapis. Fine blue, best quality lapis lazuli from the Badakshan district of Afghanistan, or from just over the border in Russia. Better known in the trade as Russian lapis. Shipley.

Afghanistan ruby. A ruby formerly mined near Kabul and also in Badakshan. Shipley.

AFMAG. See audiofrequency magnetic fields.

AFNOR. Prefix to specifications of the French Standards Association; Associa- tion Francaise de Normalization, 23 Rue Notre-Dame-des-Victoires, Paris 2. Dodd.

A-frame. a. Two poles or legs supported in an upright position by braces or guys and used as a drill mast. Also called double mast. Long. b. An open structure taper- ing from a wide base to a narrow load- bearing top. Nichols, 2.

A-frame headgear. A steel headgear consist- ing of two heavy plate A-frames, set

A-frame headgear

astride the shaft mouth. They are braced together and carry the heavy girders which support the winding sheaves platform. It is a completely self-supporting and rigid structure and leaves more usable space around the shaft collar. It includes a guide-tower structure built over the shaft collar. A number of these headgears have been erected in the Republic of South Africa, Nelson.

African emerald. a. A deceiving name for green fluor; also for green tourmaline. Shipley. b. An emerald from the Trans- vaal. It is usually quite yellowish green; often dark and dull. Hardness, 7.5; spe- cific gravity, 2.72 to 2.79; refractive in- dex, 1.58 to 1.59; birefringence, 0.007. Shipley.

African jade. Green grossularite. Same as Transvaal jade. Shipley.

African nephrite. Same as Transvaal neph-

rite. Shipley.

African pearl. True pearl found in small quantities on the east coast of Africa be- tween Zanzibar and Inhambane. Shipley.

African tourmaline. a. A trade term some-

times applied to all yellowish-green to bluish-green tourmaline whether or not from Africa. Same as Transvaal tourma- line. Shipley. b. A term sometimes used especially for fine, almost emerald-green tourmaline from southwest Africa. Ship- ley.

afterblast; inrush. During an explosion of methane and oxygen, carbon dioxide and steam are formed. When the steam con- denses to water a partial vacuum is cre- ated, which causes an inrush or what is known as an afterblast. Cooper, p. 195. afterblow. Continued blowing of air through Bessemer converter after flame has dropped, for removal of phosphorus in steel production. Pryor, 3.

afterbreak. In mine subsidence, a move-

ment from the sides, the material sliding inward, and following the main break, as- sumed at right angles to the plane of the seam. The amount of this movement de- pends on several factors, such as the dip, depth of seam, and nature of overlying materials. Lewis, p. 618.

afterburst. a. A rock burst is sometimes fol-

lowed by a further tremor as the ground adjusts itself to the new stress distribution. This is called an afterburst. Spalding. b. In underground mining a sudden collapse of rock subsequent to a rock burst. Pryor, 3. after contraction. The permanent contrac- tion (usually expressed as a linear percent- age) that may occur if a fired or chemically bonded refractory product is refired under specified conditions of test. Fire clay re- fractories are liable to show after contrac- tion if exposed to a temperature above that at which they were originally fired. Com- pare firing shrinkage. Nelson.

aftercooler. A device for cooling compressed air between the compressor and the mine shaft. By cooling and dehumidifying the air, and thus reducing its volume, the ca- pacity and efficiency of the pipeline is increased. See also intercooler. Nelson. aftercooling. The cooling of a reactor after it has been shut down. L@L.

afterdamp; aftergases. The mixture of gases which remain in a mine after a mine fire or an explosion of firedamp. It consists of carbonic acid gas, water vapor (quickly condensed), nitrogen, oxygen, carbon mon- oxide, and in some cases free hydrogen, but usually consists principally of carbonic

acid gas and nitrogen, and is therefore irrespirable. See also blackdamp. Fay.

after expansion. The permanent expansion (usually expressed as a linear percentage) that may occur when a refractory product that has been previously shaped and fired, or chemicaily bonded, is refired under specified conditions of test. Such expansion may take place, for example, if the prod- uct contains quartz or kyanite, or if bloat- ing occurs during the test. Compare firing expansion. Dodd.

afterfire. See afterrunning. Institute of Petro- leum, 1961.

aftergases. Gases produced by mine explo- sions or mine fires. Fay.

afterheat. The heat produced by the contin- uing decay of radioactive atoms in a nu- clear reactor after the fission chain reaction has ceased. Most of the afterheat is due to the decay of fission products. L@L,

afterleaving. Corn. Tailings sludge from the tin mines. Hess.

afterrunning; afterfire; running on. The fir- ing of an internal-combustion engine after the ignition has been switched off. Insti- tute of Petroleum, 1961.

aftershock. A shock following the principal earthquake, usually fading out slowly. Schieferdecker.

aftersliding. In mine subsidence, and inward movement from the side, resulting in a pull or draw beyond the edges of the workings. Briggs, p. 43.

Aftonian. Post-Nebraskan interglacial period. A.G.I, Supp.

afwillite. A hydrated calcium silicate, 3CaO. 2S8i02.3H2O; it is formed when portland cement is hydrated under special condi- tions and when calcium silicate is auto- claved (as in sand-lime brick manufac- ture). Dodd.

Ag Chemical symbol for silver. Handbook of Chemistry and Physics, 45th ed., 1964, p. B-1.

against the air. In a direction opposite to that in which the air current moves. To fire shots ‘‘against the air,” is to fire shots in such an order that the shot firer travels against the air. Fay.

agalite. Fibrous talc, pseudomorphous after enstatite. Fay.

agalmatolite. Essentially a hydrous silicate of aluminum and potassium, corresponding closely to muscovite. A secondary or altera- tion product. A soft waxy mineral used for carvings by the Chinese. See also pinite. Also called lardstone. Fay.

agaphite. A variety of Persian turquoise. Standard, 1964.

agar. An organic substance derived from cer- tain species of seaweed, which forms a thin, gelatinous liquid when added to boiling water and on cooling forms a firm, jellylike mass. Used in surveying drill holes with a Maas compass. Long.

agaric mineral. a. A soft, light, pulverulent hydrated silicate of magnesium found in Tuscany, Italy, from which floating bricks can be made. Fay. b. A light, chalky de- posit of calcium carbonate formed in caverns or fissures of limestone. Also called rock milk. Webster 3d.

agate. A kind of silica consisting mainly of chalcedony in variegated bands or other patterns commonly occupying vugs in vol- canic and other rocks. A.G.J. Supp.

agate glass. Glass made by blending two or more colored glasses or by rolling trans- parent glass into powdered glass of various colors during the melting. Webster 3d.

agglomerate

agate jasper. An agate consisting of jasper, containing veinings of chalcedony. Dana 6d, p. 189.

agate opal. Opalized agate. Fay.

agate shell. Same as agate snail, a large land snail of no gemmological interest. Shipley.

agate ware. a. An enameled iron or steel ware used for household utensils. Used ex- tensively as table equipment in miners’ camps and boarding houses. Fay. b. Pot- tery, veined and mottled to resemble agate. Standard, 1964. c. Bodies formed by blend- ing differently colored clays (known as solid agate), or by coloring surfaces with differently colored slips. C.T.D.

agatiferous. Producing or containing agate. Shipley.

agatine. Like or pertaining to agate. Shipley.

agatize. To change into, or cause to resemble an agate. Shipley.

agatized wood. A variety of silicified wood pe resembles any variety of agate. Ship- ey.

AGC Automatic gain control. An electronic device used in seismic reflection amplifiers to keep the overall recording level from varying more than a controlled amount. A.G.I.

age. a. Any great period of time in the his- tory of the earth or the material universe that is marked by special phases of physical conditions or of organic development; an

eon; as, the age of mammals. Standard,

1964. b. One of the minor subdivisions of geologic time, a subdivision of the epoch, and correspondent to the stage or forma- tion: recommended by the International Geological Congress. Standard, 1964.

Agecroft device. A device placed in the rail track to arrest a forward runaway tram. The front axle of a descending tram trav- eling at normal speed depresses the catch and allows it to drop back in time for the back axle to pass over. Should the tram be traveling at excessive speed, the tail end of the catch arrests the rear axle. Mason, Vie PeOIOs

aged. Approaching baselevel reduction; ap- plied to the configuration of ground. Standard, 1964.

age equation. An equation which gives the time during which radioactive processes have been going on in a closed system, in terms of present values of radioactivity and of radiogenic helium or lead, or from pres- ent abundance ratios of radiogenic lead isotopes. Hess,

age-hardening. Hardening by aging, usually after rapid cooling or cold working. See also aging, d. ASM Gloss.

agent. a. The manager of a mining property. Zern. b. On a civil engineering contract, the responsible representative of the con- tractor, acting for him in all matters. Ham. c. Before nationalization in Great Britain, the term referred to the chief official of a large coal mine or group of mines under the same ownership. After nationalization, the equivalent term is group manager. Nelson. d. A chemical added to pulp to produce desired changes in climate of sys- tem. Pryor, 3.

age ratio. The ratio of daughter to parent isotope; the term is often used to indicate a ratio that is perturbed by some factor and, therefore, not indicative of the abso- lute age of the mineral. A.G.J.

agglomerate. a. A breccia composed largely or entirely of fragments of volcanic rocks. More specifically, a heterogeneous mixture of fragments of volcanic and other rocks

agglomerate

filling the funnel or throat of an extinct or quiescent volcano. Fay. b. To collect into a ball, heap, or mass; hence, to gather into a mass or Cluster. Webster 3d. c. Contem- poraneous pyroclastic rock containing a predominance of round or subangular frag- ments larger than 32 millimeters in diam- eter. A.G.I.

agglomerate belt flotation. A coarse-fraction

concentration method used in milling peb- ble phosphate in which conditioned feed at 70 to 75 percent solids, is placed on a flat conveyor belt traveling at a rate of about 75 feet per minute. Water sprayed on the surface of the pulp aerates the pulp causing agglomerates of phosphate particles to float to the side of the belt for removal. The silica fraction travels the length of the belt and is permitted to flow off the opposite end. Baffles are positioned at ap- propriate points along the belt to stir the material so that trapped phosphate par- ticles are given an opportunity to float. Concentrate from the first belts or rougher operation, is cleaned on a second belt for further silica removal. Tailings from the cleaner belt are recycled to the rougher circuit. Arbiter, p. 336.

agglomerated. Bonded aggregate. VV. agglomerate screening. A coarse fraction concentration method used in milling peb- ble phosphate that is based on flowing re- agentized feed over a submerged sloping, stationary screen. Aglomerated phosphate particles float on top of the screen and are recovered at the lower end. Sand particles pass through the screen and are removed as a tailings fraction. Each screen section is approximately 3 feet wide by 4 feet long and treats 2 to 3 tons per hour of feed. Arbiter, pp. 336-337.

agglomerate tabling. A coarse fraction con- centration method used in milling pebble phosphate that involves feeding shaking tables with reagentized pulp diluted to about 30 to 35 percent solids. Conditioned phosphate particles skim across the table as an agglomerate float. Sand particles caught in the rifles discharge into a tail- ings launder at the end of the table. Arbi- ter, p. 336.

agglomerating value. A measure of the bind- ing qualities of coal but restricted to describe the results of coke-button tests in which no inert material is heated with the coal sample. Compare agglutinating value. A.G.I.

agglomeration. a. In ore beneficiation, a concentration process based on the adhesion of pulp particles to water. Loosely bonded associations of particles and bubbles are formed which are heavier than water; flowing-film gravity concentration is used to separate the agglomerates from non- agglomerated particles. Gaudin, pp. 334- 335. In metallurgical language, agglom- eration also refers to briquetting, noduliz- ing, sintering, etc. b. See kerosine flotation. Mitchell, p. 572.

agglutinate. A pyroclastic deposit consisting of an accumulation of originally plastic ejecta (chiefly volcanic bombs and drib- let) and formed by the coherence of the fragments upon solidification. The cement is the glassy skin of the fragments at their point of contact. Distinguished from ag- glomerate by the presence of a glassy ce- ment, by the occurrence of fragments of spalled-off scoria in the interstices between the blocks, and by the general absence of an ash or tuff matrix. A.G.I.

agglutinating power. See index. Nelson.

agglutinating value. A measure of the bind- ing qualities of a coal and an indication of its caking or coking characteristics. Applicable with reference to the ability of fused coal to combine with an inert material as sand. Compare agglomerating value. A.G.I.

agglutinating-value test. A laboratory test of the coking properties of coal, in which a determination is made of the strength of buttons made by coking a mixture of powdered coal and 15 to 30 times its weight of sand. Bureau of Mines Staff.

aggradation. a. The natural filling up of the bed of a watercourse at any point of weakening of the current, by deposition of detritus. Standard, 1964. b. Specifically, the building up of fanlike graded plains by streams in arid regions by the shifting of the streams and the loss of the water in the dry soil. Contrasted with degrada- tion. Standard, 1964. c. The process of building up a surface by deposition. A.G.I. d. The growth of a permafrost area. A.G.JI. See also accretion.

aggradation plain. A topographic plain built up by aggradation in arid districts. It is begun by the building up of the bed of a stream, at the foot of a declivity, forming a plain with a nearly straight longitudi- nal profile, that may become a very broad plain of deposition. Standard, 1964.

aggrading stream. Synonym for upgrading stream. A.G.I.

aggregate. a. Sand, gravel, or any clastic material in a bedded iron ore, sometimes so abundant as to make it resemble a puddingstone. Arkell. b. Uncrushed or crushed gravel, crushed stone or rock, sand, or artificially produced inorganic materials, which form the major part of concrete. Taylor. c. To bring together; to collect or to gather into a mass. Webster 3d. d. Composed of mineral or rock frag- ments; composed of mineral crystals of one or more kinds. Webster 3d. e. See concrete aggregate; lightweight expanded clay aggregate. Dodd,

aggregated. Packed particles. VV.

aggregated ore; aggregated sulfide. Massive sulfide. in which the sulfide constitutes 20 percent or more of the total volume. A.G.I.

aggregated sulfide. See aggregated ore. A.G.I.

aggregate polarization. Polarization in a rock thin section in which the constituent min- erals cannot be individually recognized. Webster 3d.

aggregate structure. A randomly oriented mass of separate little crystals, scales, or gains that extinguish under the polarizing microscope at different times. Fay.

aggressive magma. A magma that forces its way into place. Synonym for invasive magma. A.G.I.

aggressive water. Natural water with a total hardness of less than 60 p.p.m., expressed as calcium carbonate, and carrying dis- solved oxygen and carbon dioxide close to the point of saturation;. water containing corrosive matter. Bennett 2d, 1962 Add.

Agilite. Talc. Bennett 2d, 1962.

aging. a. The storing of ceramic raw ma- terials (that is, clays, clay slips, enamel slips, glazes, etc.) before processing. Bu- reau of Mines Staff. b. The change occur- ring in slips or powders with the lapse of time. ASTM C286-65. c. Curing of pre- pared ceramic materials by a definite pe-

caking

Aglite

riod of storage under controlled conditions. ACSG, 1963. d. In a metal or alloy, a change in properties that generally occurs slowly at room temperature and more rap- idly at higher temperatures. See also age- hardening; artificial aging; interrupted aging; natural aging; overaging; precipi- tation hardening; precipitation heat treat- ment; progressive aging; quench aging; strain aging. ASM Gloss. Also spelled age- ing. e. A change in the properties of a substance with time. Nelson. f. In electri- cal engineering, aging usually implies a change in the magnetic properties of iron, for example, increase of hysteresis, loss of sheetsteel laminations, etc. Nelson.

Agitair flotation machine. Rectangular trough

divided into interconnected square com- partments, into each of which low-pressure air is stirred through a system of revolv- ing teeth and stationary baffles to produce copious air bubbles which search the min- eralized pulp flowing from feed to discharge end of the trough. These bubbles lift aero- philic particles to an overflow, froth, laun- der while hydrophilic ones remain in the pulp, and are separately discharged. Pryor, 3.

agitating lorry. A truck mixer. Ham. agitation. a. Vigorous stirring of pulp in a

tank by low-pressure air or mechanical means to prevent settlement. Also used in the leaching of gold and other minerals from finely ground aqueous suspension in which oxygen is essential to chemical re- action, for example, the cyanide process. Pryor, 3. b. A strong shaking, stirring, or moving. Bureau of Mines Staff.

agitation dredging. Consists in pumping the

discharge directly into the sea and using the tide to carry the fines to deeper water areas. Agitation dredging is employed only during ebb tide in tidal estuaries having swift tidal flows that will disperse the ac- cumulations of silt. Carson, 2, p. 56.

agitation ratio. In older type gravity con- centrators, such as tables and vanners, the ratio between the average diameter of a mineral particle and the diameter of a gangue particle that travels at equal speed. Bureau of Mines Staff.

agitator. a. A tank in which very finely crushed ore is agitated with leaching solu- tion. Usually accomplished by means of a current of compressed air passing up a central pipe and causing circulation of the contents of the tank. Sometimes called a mixer. C.T.D. b. A device used to stir or mix grout or drill mud. Not to be confused with shaker or shale shaker. Long. c. A device used to bring about a continuous vigorous disturbance in a pulp, frequently used to assist bubble formation. B.S. 3552, 1962. d. An implement or apparatus for shaking or mixing. Webster 3d. e. Pac. See settler. Fay.

aglaite. A pseudomorph of spodumene in which the spodumene has been replaced by muscovite either as pinite or as visible plates, Also called pihlite and cymatolite in the belief that the material was a new mineral. Hess.

A-glass. A fiber glass containing 10 to 15 percent alkali (calculated as NasO). Dodd.

Aglite. A trade name for a lightweight ex- panded clay aggregate made by the Butter- ley Company, Ltd., Derby, England, from colliery shale by the sinter-hearth process. The bulk density is: % to 34 inch, 31 pounds per cubic foot; % to %6 inches, 35 pounds per cubic foot; finer than %6

Aglite

inch, 50 pounds per cubic foot. Dodd.

agmatite. a. Migmatite containing xenoliths. A.G.I. Supp. b. Fragmental plutonic rock with more or less granitic cement. A.G.I, Supp. c. A broken rock in which pegmatite has filled the cracks and formed a three- dimensional network. Hess.

agnesite. Corn. An early name for bismutite. Fay.

agonic line. One of several lines on the earth’s surface, on which the direction of the magnetic needle is truly north and south; a line of no magnetic declination. Standard, 1964.

agpaite. Applied to the feldspathoidal rocks of Ilimansak, Greenland, including sodalite foyaite, naujaite, lujaurite, and kakortokite. Holmes, 1928.

agpaitic. Applied to a process of mineral formation distinguished from an ordinary granitic process by an excess of alkali (especially sodium) as a result of which the amount of alumina is insufficient for the formation of aluminum silicates. Hess.

agreement. The formal document by which the contractor and the authority mutually agree to comply with the requirements of the drawings, specification, schedule, con- ditions of tendering, and general conditions of contract and the tender. See also con- tract. Nelson.

agricolite. An adamantine colorless or yellow bismuth silicate, BiSisO., crystallizing in the monoclinic system. Fay.

agricultural drain. Earthenware or porous concrete pipes of about 3 inch internal diameter, laid end to end below ground with open joints in order to drain the sub- soil. Synonym for land drain. Ham.

agricultural geology; agrogeology. The ap- plication of geology to agricultural prob- lems and to soil improvement. Schiefer- deckr.

agricultural hydrate. A relatively coarse, un- refined form of hydrated lime that is main- ly used for neutralizing soil acidity and for purposes where high purity and uniform- ity are unnecessary. Boynotn.

agricultural lime. a. A lime whose calcium and magnesium content is capable of neu- tralizing soil acidity. ASTM C51-47. b. Lime slaked with a minimum amount of water to form calcium hydroxide. CCD 6d, 1961.

agricultural pipes. See field-drain pipe. Dodd

agricultural stone. A finely ground limestone used as an alternative to lime to neutralize or reduce acidity of soils. BuMines Bull. 630, 1965, p. 886.

Agrifos. Colloidal phosphatic clay. Used as a fertilizer. Bennett 2d, 1962.

agrite. A brown, mottled, calcareous stone. Schaller.

agrogeology. Synonym for agricultural geol- ogy. A.G.I,

aguilarite. A sectile silver selenide, AgpS. AgeSe, occurring in skeleton dodecahedral crystals. Fay.

ahlfeldite. A hydrate nickel selenite; prob- ably triclinic; rose colored; vitreous luster ; no cleavage; conchoidal fracture; strongly pleochroic, X rose, Y pale green, Z brown green; from Pacajake, Bolivia. American Mineralogist, v. 39, September-October 1954, p. 850.

A-horizon. In a soil profole, the uppermost zone from which soluble salts and colloids have been leached and in which organic matter has accumulated. Synonym for zone of eluviation, See also B-horizon. A.G.I.

aiguille. Fr. An instrument for boring holes in stone or other masonry or holes used in blasting. Webster 3d.

aikinite. a. A blackish, lead-gray sulfide of lead, copper, and bismuth, 3(Pb,Cu.)- S.BiS;, that crystallizes in the orthorhom- bic system; needle ore. Fay. b. A pseudo- morph of wolframite after scheelite. Ob- tained from Cornwall, England. English.

ailsyte. Derived from Ailsa Craig, Scotland, for a microgranite containing considerable riebeckite. Fay.

aimotolite. Hematolite. Dana 6d, p. 802.

AIME American Institute of Mining and Metallurgical Engineers. Statistical Re- search Bureau.

air. a. The mixture of gases that surrounds the earth and forms its atmosphere; com- posed by volume of 21 percent oxygen and 78 percent nitrogen; by weight about 23 percent oxygen and 77 percent nitrogen. It also contains about 0.03 percent carbon dioxide, some aqueous vapor, and some argon. Fay. b. The current of atmospheric air circulating through and ventilating the workings of a mine. Fay. c. To ventilate any portion of the workings. Fay. d. At- mospheric air delivered under compres- sion to bottom of drill hole through the drill stem and used in place of water to clear the drill bit of cuttings and to blow them out of the borehole. See also air cir- culation. Long. e. Air piped under com- pression to work areas and used to operate drilling or mining machinery. Long.

air adit. An adit driven for the purpose of ventilating a mine. Fay.

air-avid surface. A surface that seems to pre- fer contact with air to contact with water. A particle (or mineral) of this sort will adhere to an air bubble and float out of a flotation pulp; otherwise, the particle will not float. Also called water-repellent surface. Compare water-avid surface. New- ton, p. 98.

air barrage. The division of a ventilation gallery in a mine by an airtight wall into two parts; the air is led in through the one part and back through the other part. Stoces, v. 1, p. 534.

air base. In aerial photographic mapping, the distance between the exposure stations of two overlapping aerial photographs. See also base line. Seelye, 2.

air bell. a. In froth flotation, the small air pocket inducted or forced into the pulp at depth, for example, bell and the two- walled semistable bubble after emergence from pulp into froth have different char- acteristics and gas-to-liquid, area-to-volume relationships, hence the distinction. These bubbles vary in attractive and retaining power for aerophilic mineral grains, and are a critical component of the flotation process. Also called air bubble. Pryor, 3. b. A bubble of irregular shape formed gen- erally during the pressing or molding op- erations in the manufacture of optical glass. ASTM C162-66.

air belt. In a cupola furnace, an annular air space around the furnace, from which air is forced into the furnace. Henderson.

airblast. a. A term improperly used by some diamond drillers as a synonym for air cir- culation. See also air circulation, a. Long. b. A disturbance in underground workings accompanied by a strong rush of air. The rush of air, at times explosive in force, is caused by the ejection of air from large underground openings, the sudden fall of

air breakers

large masses of rock, the collapse of pillars, slippage along a fault, or a strong current of air pushed outward from the source of an explosion. Long.

airblasting. A method of blasting in which compressed air at very high pressure is piped to a steel shell in a shot hole and discharged. B.S. 3618, 1964, sec. 6.

air block. Air trapped in the upper end of an unvented inner tube of a double-tube core barrel, which, when sufficiently com- pressed, acts like a solid and stops further advance of core into the inner tube. Also called air cushion. Long.

airborne electromagnetic prospecting. Elec- tromagnetic surveys carried out with air- borne instruments. Since 1950, an increas- ing proportion of such surveys have been carried out in this manner since advantages in cost reduction and speed are great. Dobrin, p. 368.

airborne geophysical anomaly. A geophysical anomaly related to geologic formations that can be detected by airborne equipment. Hawkes, 2, p. 320.

airborne magnetometer. A device used to measure variations in the earth’s magnetic field while being transported by an aircraft. Same as aerial magnetometer. A.GI.

airborne radiation thermometer. A device used to measure surface temperature of the ocean as a function of reflected radiation. Abbreviation, art. Hy.

airborne scintillation counter. Any scintilla- tion counter especially designed to measure the ambient radioactivity from an aircraft in flight. The instrument measures gamma radiation by employing a phosphor which emits a minute flash of light on absorbing a gamma ray. A photomultiplier tube con- verts the light flashes into an electrical current or voltage variation which is pro- portional to the intensity of gamma radia- tion. A.G.I.

airborne sealing. A process for the general, as opposed to local, repair of a gas retort by blowing refractory powder into the sealed retort, while it is hot; the powder builds up within any cracks in the refrac- tory brickwork and effectively seals them against gas leakage. Compare spray weld- ing. Dodd,

airbound. The condition of a pipeline where- in air entrapped in a summit prevents the free flow of water through it. Seelye, 1.

air box. a. A rectangular wooden pipe or tube made in lengths of from 9 to 15 feet for ventilating a heading or a sinking shaft. Fay. b. A box for holding air. Fay. c. The conduit through which air for heating rooms is supplied to a furnace. Standard, 1964.

airbrake. A mechanical brake operated by air pressure acting on a piston. Nelson.

air breakers. A method of breaking down coal by the use of high-pressure compressed air. The method was first introduced in the United States about 1947. As used today, the power unit is normally an elec- trically driven air compressor operating at pressures of 10,000 to 12,000 pounds per square inch, The high-pressure air is con- ducted through a steel pipeline to the working face, and copper tubing or wire- braided rubber hose is used to connect the supply pipeline to the air-breaker shell which discharges the air in the shothole. Normally, one or two shells are in use in a working place at any one time, and the simplicity of the operation is such that the

air breakers

same shell can be discharged 16 to 20 times per hour. McAdam II, pp. 91-92.

air brick. A hollow or pierced brick built into a wall to allow the passage of air. Fay.

air bridge. a. A passage through which a ventilating current is conducted over an entry or air course; an overcast. Fay. b. See air crossing. B.S. 3618, 1963, sec. 2.

air chamber. A vessel installed on piston pumps to minimize the pulsating discharge of the liquid pumped. The chamber con- tains air under pressure and is fitted with an opening on its underside into which some of the liquid from the pump is forced upon the delivery stroke of the pis- ton. The air acts as a cushion to lessen the fluctuation of the liquid flow between the suction and delivery strokes of the pis- ton. Crispin.

air change. The quantity of infiltration or ventilation air in cubic feet per hour or per minute divided by the volume of the room gives the number of so-called air changes during that interval of time, and tables of the recommended number of such air changes for various-type rooms are used for estimating purposes. Strock, 10.

air channels. In a reverberatory furnace, flues under the hearth and fire bridge through which air is forced to avoid over- heating. Henderson.

air circulation. a. A large volume of air, under compression, used in lieu of a liquid as a medium to Cool the bit and eject the cuttings from a borehole. Also called air flush. Long. b. A form of air travel in which the air returns almost all the way back to the point from which it started and some may even return the entire way v6 make recirculation possible. Lewis, p.

air clamp. Any type of clamping device operated by pneumatic pressure. Crispin.

air classification. a. In powder metallurgy,

the separation of powder into particle-size fractions by means of an airstream of con- trolled velocity; an application of the principle of elutriation. ASM Gloss. b. Sorting of finely ground minerals into equal settling fractions by means of air currents. These are usually controlled through cyclones which deliver a coarse spigot product and a relatively fine vorti- cal overflow. See also infrasizer. Pryor, 3. c. A method of separating or sizing granu- lar or powdered materials such as clay, through deposition in air currents of vari- ous speeds. This principle is widely used in continuous pulverizing of dry materials, such as frit, feldspar, limestone, and clay. See also air classifier; air elutriator. Enam. Dict.

air classifier. An appliance for approximately sizing crushed minerals or ores by means of currents of air. See also air elutriator. C.T.D:

air cleaning. A coal cleaning method that utilizes air tables to remove the dust and waste from coal, Air cleaning requires that the coal contain less than 5 percent of sur- face moisture as a rule. It is effective only in the coarse sizes (plus 10 to 28 mesh) and is best suited to coals having a sharply defined line between coal and refuse mate- rial. Predrying to reduce the moisture con- tent of the coal head of the air table treatment is not uncommon. It is a less expensive and also,a less accurate method of cleaning coal than the wet cleaning method. Kentucky, pp. 299-300.

air clutch. Either a friction or mechanical clutch that is engaged by air pressure and generally disengaged by spring action. ASM Gloss.

air cock. a. Petcock-type valve for bleeding off air trapped in pumps, pump lines, or hydraulic systems. Long. b. A cock for letting off air. Fay.

air compartment. An airtight portion of any shaft, winze, raise, or level used for venti- lation. B.S. 3618, 1963, sec. 2.

air compressor. A machine which draws in air at atmospheric pressure, compresses it, and delivers it at a higher pressure. It may be of the reciprocating, centrifugal, or ro- tary (vane) type. C.T.D. See also after- cooler; air receiver; compressed air; duplex compressor; power-driven compressor; ro- tary compressor; straight-line compressor; Sullivan angle compressor; turbocompres- sor. Lewis, pp. 671-672.

air conditioning. The simultaneous control, within prescribed limits, of the quality, quantity, and temperature-humidity of the air in a designated space. It is essentially atmospheric environmental control. Con- trol of only one or two of these properties of the atmosphere does not constitute air conditioning. The definition and correct usage require that the purity, motion, and heat content of the air must all be main- tained within the prescribed limits. Hart- man, p. 3.

air-conditioning processes. When condition- ing is designed to perform only one or a limited number of functions, then it should be so designated. These are more correctly termed air-conditioning processes, and they include dust control, ventilation, dehumidi- fication, cooling, heating, and many others. Hartman, p. 3

air course. a. Ventilating passage under- ground. Pryor, 3. b. A passage through which air is circulated. Particularly a long passageway driven parallel to the workings to carry the air current. Fay, c. See airway. Nelson.

air coursing. The system of colliery ventila- tion, introduced about 1760, by which the intake air current was made to traverse all the underground roadways and faces before passing into the upcast shaft. Nel- son.

air creep. Stain formed by air entering at edges of mica sheets and penetrating along cleavage planes. Skow.

air crossing. A bridge where a return airway passes over (overcast) or under (under- cast) an intake airway. It is generally con- structed with bricks, or concrete and steel joists, and the whole made airtight to pre- vent intermixing of the two air currents. The act requires an air crossing to be so constructed as not to be liable to be dam- aged in the event of an explosion. Nelson. Also called air bridge.

air current. a. The flow of air ventilating the workings of a mine. Also called airflow; air quantity. B.S. 3618, 1963, sec. 2.b. A body of air moving continuously in one direction. Jones.

air cushion. a. Air trapped in the bottom of a dry borehole by the rapid descent of a tight string of borehole equipment. Long. b. Synonym for air block. Long.

air cyclone. Primarily a vessel for extracting dust from the atmosphere. See also cyclone. Nelson.

air displacement pump. A pump consisting of a closed vessel from which water is expelled

aired ware

through a delivery valve and pipe by means of compressed air admitted to the top of the vessel. Also called displacement pump. B.S. 3618, 1963, sec. 4.

air distribution. Supplying air in the desired amounts to the various working places in a mine. Hartman, p. 250.

air dome. A cylindrical or bell-shaped con- tainer closed at the upper end and at- tached in an upright position above and to the discharge of a piston-type pump. Air trapped inside the closed cylinder acts as a compressible medium, whose expan- sion and contraction tends to reduce the severity of the pulsations imparted to the liquid discharged by each stroke of a pump piston. Also called bonnet; pressure dome. Long.

air door. a. A door erected in a roadway to prevent the passage of air. When doors are erected between an intake and a return airway they may be known as separation doors. Also called door; separation door; trapdoor. B.S. 3618, 1963, sec. 2. b. A door in a ventilating network that directs air in a required direction by closing part of the circulating system. Pryor, 3.

Airdox. A system for breaking down coal by which compressed air, generated locally by a portable compressor at 10,000 pounds per square inch, is used in a releasing cy]- inder, which is placed in a hole drilled in the coal. Thus, slow breaking results, with no flame, in producing a larger percentage of lump coal than is made by using ex- plosives. Its principal advantage is that it may be used with safety in gaseous and dusty mines. See also compressed-air blast- ing. Lewis, p. 114.

air drain. A passage for the escape of gases from a mold while the molten metal is being poured in. Standard, 1964.

air-dried. Of minerals, naturally dried to equilibrium with the prevailing atmos- phere. Pryor, 3.

air-dried basis. An analysis expressed on the basis of a coal sample with moisture con- tent in approximate equilibrium with the surrounding atmosphere. B.S, 3323, 1960.

air drift. a. A roadway, generally inclined, driven in stone for ventilation purposes. B.S. 3618, 1963, sec. 2. b. A drift connect- ing a ventilation shaft with the fan. Fay.

air drill. a. A small diamond drill driven by either a rotary or a reciprocating-piston air-powered motor, used principally in underground workings. Long. b. As used by miners, a percussive or rotary-type rock drill driven by compressed air. Long.

air-drill operator. See jackhammer operator. DO. Tight

air drive. Forcing compressed air into an oil- bearing bed in order to increase the flow of oil from wells. Hess.

air-dry. a. Dry to such a degree that no further moisture is given up on exposure to air. Webster 3d. Most air-dry substances contain moisture that can be expelled by heating them or placing them in a vac- uum. Fay. b. Said of timber, the moisture content of which is in approximate equi- librium with local atmospheric conditions. G.T.D.

air duct. a. Tubing which conducts air, usually from an auxiliary fan, to or from a point as required in the mine. B.S. 3618, 1963, sec. 2. b. An air box, canvas pipe, or other air carried for ventilation. Hess.

aired ware. Pottery ware that has a poor glaze as a result of volatilization of some

aired ware

of the glaze constituents. The term was used more particularly when ware was fired in saggers in coal-fired kilns, air es- caping from a faulty sagger into the kiln while kiln gases at the same time pene- trated into the sagger. The term is also sometimes applied to a glaze that has par- tially devitrified as a result of cooling too slowly between 900° and 700° C. Dodd.

air elutriation. Method of dividing a sub- stance into various particle sizes by means of air currents. The particles formed are of uniform density. Bennett 2d, 1962.

air elutriator. An appliance for producing, by means of currents of air, a series of sized products from a finely crushed min- eral (for example, for the paint or abrasive industries). See also air classifier. C.T.D.

air embolism. Sce caisson disease. Ham.

air endway. A narrow roadway driven in the coal seam parallel and close to a winning headway chiefly for ventilation. The air endway usually acts as a return and is con- nected at intervals of 10 yards or so to the headway by crosscuts. See also companion heading. Nelson.

air-entrained concrete. Concrete used for road construction in the United States, having about 5 percent of air in its com- position. Although less dense than ordinary concrete, it has very high resistance to frost. The strength loss as compared with ordinary concrete is about 5 percent for each 1 percent of air entrained. Ham.

air entraining. The addition of a material to portland cement clinker during grinding, or to concrete during mixing, for the pur- pose of reducing the surface tension of the water so that 4 to 5 percent (by volume) of minute air bubbles become trapped in the concrete. This improves workability and frost resistance and decreases segrega- tion and bleeding. The agents used as addi- tions include: 0.025 to 0.1 percent of al- kali salts of wood resins, sulfonate deter- gents, alkali naphthenate, or triethanola- mine salts; or 0.25 to 0.5 percent of the Ca (calcium) salts of glues (from hides) ; or 0.25 to 1.0 percent of Ca (calcium) lignosulfonate (from papermaking). Dodd.

air-entraining agent. An admixture to port- land cement or to a concrete mix. It is usually a resin which entrains the air in very fine bubbles. Its purpose is to increase both workability of the wet concrete and its frost resistance when hardened. Ham.

airfield soil classification. Classification pub- lished in Casagrande in the United States in 1948, based on sieve analyses and con- sistency limits. Cohesive soils can be di- vided into those with a liquid limit above or below 50 percent. The former are, in general, clays and the latter, silts. Ham.

air filter. A device for cleaning compressed air. Hansen.

air-float clays. Clays of a fine state of sub- division as the result of separation by an air process, after grinding. CCD 6d, 1961.

air-float table. Shaking table in which ore is worked dry, air being blown upward through a porous deck so as to dilate the material. Pryor, 3.

airflow. See air current, a. B.S. 3618, 1963, sec. 2,

airflow equalizing device. A flow-equalizing device which is fitted to tube breathing apparatus. There are two kinds in general use, one consisting of a flexible corrugated rubber tube and the other a canvas fabric bag. On inspiration, air is drawn partly

from the equalizer, which is reduced in volume, and partly from the tube. On ex- piration, the equalizer restores itself to its original volume and in doing so draws air through the tube. Thus the air is kept flowing very nearly in a continuous stream, and the wearer, without the aid of bel- lows or rotary blower, experiences very little resistance to breathing. Mason, v. I, p. 327.

airflow meter. An instrument which meas- ures and shows directly on a scale the flow of air in a pipe or hose in cubic feet per minute. Nelson.

air flush. Synonym for air circulation. Long.

air flushing. The circulation of air through the drilling apparatus during drilling to cool the bit and to remove the cuttings from the hole. B.S. 3618, 1963, sec. 2.

air foam extinguisher. An extinguisher which produces a foam somewhat similar to that produced by a chemical foam extinguisher, therefore, it can be used for the same pur- poses. However, unlike the chemical foam type, this extinguisher can be recharged underground by simply filling the outer container with water and inserting a sealed metal charge holding foam concentrate and a propellent charge of carbon dioxide. McAdam, p. 117.

airfoil fan. A fan with an _airfoil-shaped blade which moves the air in the general direction of the axis about which it rotates. Strock, 10.

air furnace. Malleable iron furnace. Bureau of Mines Staff.

air gap. a. The distance between the surface of the electrode and the oscillator plate. It is usually necessary to avoid particular gap dimensions in which resonance damp- ing occurs with acoustic waves generated by the oscillator plate. AM, 1. b. The dis- tance between passing material and tip of attracting magnetic pole, in a magnetic separator. Pryor, 3. c. The gap between rotor and stator of a dynamo or an elec tric motor. Pryor, 3.

air gas. a. A combustible gas made by charg- ing air with the vapor of some volatile hydrocarbon mixture (as gasoline) and used for lighting and heating. Webster 3d. b. A producer gas consisting chiefly of carbon monoxide and nitrogen and made by blowing air into a producer. Webster

air gate. a. Mid. An underground road- way used principally for ventilation. Fay. b. An air regulator. Fay. c. In molding, an orifice through which the displaced air and gases escape from the mold while the molten matter is filling it. Fay.

airhammer. a. Sharp, vibratory impacts in a liquid pump or piping system caused by entrapped air. Long. b. Reciprocating mo- tion induced in a drill string by excessive air pressure at face of drill bit when air is used in lieu of a liquid as a bit coolant and cuttings removal agent. Long. c. A pneumatically actuated hammer. Long. d. A tool in which a hammerhead is activated by means of compressed air. The air is conducted to the tool through a hose. A trigger starts or stops the admission of air to the hammer. Crispin.

airhammer operator. One who breaks as- phalt, concrete, stone, or other pavement, who loosens earth, digs clay, breaks rocks in trimming bottom or sides of trenches or other excavations, or who reduces the size

air intake

of large stones, using an airhammer. D.O.T. Supp.

air-hardened steels. Alloy steels in which a certain degree of hardness has been induced merely by air cooling under controlled con- ditions. Camm.

air-hardening refractory cement; air-harden- ing refractory mortar. See chemically bonded refractory cement. Dodd.

air-hardening refractory mortar. See air- hardening refractory cement. Dodd.

air-hardening steel. Steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous mediums from a temperature above its transformation range. The term should be restricted to steels that are capable of being hardened by cooling in air in fairly large sections, about 2 inches or more in diameter. Same as self-hardening steel. ASM Gloss.

airhead; airheading. S. Staff. A smaller drift driven parallel to the main haulageway for an air course. A connecting crosscut is called a spout. Fay; Hess.

air heater. An appliance to warm the air as it enters the downcast shaft or intake drift. In countries where the winter is very cold, such as Poland and Russia, nearly all mines are equipped with air heaters. A few British mines have oil-fired air heaters, mainly to prevent the accumulation of ice in wet downcast shafts or on winding ropes. Nelson.

air-heating furnace. A furnace used for heat- ing air to warm a room or building. Hess.

air heave structure. Small crumplings, which die out downward, found in laminated sands and which are presumed to be formed by rise of air trapped in sand at low tide. Pettijohn.

air hoist. a. Hoisting machinery operated by compressed air, Fay. b. A small portable hoisting machine usually mounted on a column and powered by a compressed air motor. Also called tugger. Long.

airhole. a. A small excavation or hole made to improve ventilation by communication with other workings or with the surface. See also cundy. B.S. 3618, 1963, sec. 2. b. A venthole in the upper end of the inner tube of a double-tube core barrel to allow air and/or water entrapped by the advanc- ing core to escape. Long, c. A void, cavity, or flaw in a casting or bit crown. Long.

air horsepower. a. The rate at which energy is used in horsepower units, in moving air between two points, B.S. 3618, 1963, sec. 2. b. The horsepower in an air current is usually expressed in the form: Horsepower

(hp) = 33,000

lating pressure in pounds per square feet and Q equals quantity of air in cubic feet per minute. Nelson.

air hp Abbreviation for air horsepower. BuMin Style Guide, p. 58.

airing. Smelting operation in which air is blown through molten copper in a wire bar or anode furnace. Sulfur is removed as SOs: and impurities are slagged off. Pryor, 3.

air intake. A device for supplying a com- pressor with clean air at the lowest possible temperature. A simple screen in the form of a box over the end of the intake pipe may be used if the air is normally quite free from dirt, but if much dirt is in the air, some form of air filter of suitable de- sign should be provided. The cooler the

, where P equals venti-

air intake

intake air, the greater is the capacity of the compressor; a drop of 5° in tempera- ture represents a gain in capacity of ap- proximately 1 percent. In hot climates the intake should be placed on the coolest side of the compressor house. Lewis, p. 671.

air jig. A machine in which the feed is stratified by means of pulsating currents of air and from which the stratified products are separately removed. B.S. 3552, 1962.

air lance. Length of piping down which com- pressed air is blown, to stir settled sands or to free choked passages. Pryor, 4.

air lancing. a. Removing or cutting away loose material by means of compressed air, using an air lance; airblasting. Henderson. b. In founding, a cleaning operation, as cleaning sand from molds and castings, using an air lance; airblasting. Henderson. c. Also means opening passages for molten materials. Bureau of Mines Staff.

air leakage. a. The short-circuiting of air from intake to return airways (through doors, stoppings, wastes, and old workings) without doing useful work in flowing around the faces. The total air leakage is usually within the range of 35 to 55 per- cent of that passing through the surface fan. Nelson. b. The leakage of air in the transmission lines may be determined by filling the entire system with air at normal Operating pressure and then closing the valves on both ends of the line. Assuming that the valves are tight and all loss in pressure is due to leakage, the cubic feet of free air lost per minute through leakage

5V is: Q= -—, where Q equals leakage in T

cubic feet per minute of free air at time of shutting down, V equals total volume of air in the system at time of shutting down reduced to cubic feet of free air, and T equals time in minutes from shutting down until the gage has dropped to zero. Lewis, p. 679.

air leg. a. A cylinder operated by compressed air, used for keeping a rock drill pressed into the hole being drilled. Ham. b. A de- vice, incorporating a pneumatic cylinder, providing support and thrust for a jack- hammer. B.S. 3618, 1964, sec. 6.

air-leg support. An appliance to eliminate much of the labor when drilling with hand- held machines. It consists of a steel cylin- der and air-operated piston, the rod of which extends through the top end of the cylinder and supports the drilling ma- chine. The air leg and machine can be operated by one man. Nelson.

airless end. The extremity of a stall in long- wall workings in which there is no current of air. The air is kept sufficiently pure by diffusion, and by the ingress and egress of tubs, men, etc. Fay.

air level. Eng. A level or airway (return airway) of former workings made use of in subsequent deeper mining operations for ventilation. Fay.

air lift. a. An apparatus used for pumping water from wells either temporarily or for a permanent water supply; for moving cor- rosive liquids such as sufuric acid; for un- watering flooded mines; for elevating mill tailings, sands, and slimes in cyanide plants ; and for handling the feed to ball mills. In operation, compressed air enters the educ- tion pipe and mixes with the water. As the water and air rise, the air expands and is practically at atmospheric pressure at the

top of the discharge pipe. The efficiency of the air lift is calculated on the basis of the foot-pounds of work done in lifting the water, divided by the isothermal work re- quired to compress the air. Lewis, pp. 686- 689. b. A method used in petroleum ex- ploitation in which gas pressure is increased artificially by driving air or natural gas into the deposit under pressure from a neigh- boring borehole, thereby forcing the petro- leum out. Stoces, v. 1, p. 478.

air-lift dredges. Dredges in which solids sus- pended in a fluid are lifted. By injecting air into a submerged pipe at about 60 per- cent of the depth of submergence, the density of the fluid column inside the pipe can be lessened, forcing the fluid