None
electric mine lamps, 319 (See E. M. L.); P. mine safety lamps, 288 (See L., M. S.) Splitting the air current, 218, 260 A. splits, 258 Effect of s. on mine potential, 203; E. on mine resist- ance, 245; E. on quan- tity, 245; E. on velocity, 244 Equal splits; Illustration, 223; General mine potential, 213; Ex., 214 Formulas Split potential, 204; S. power and s press, pot., 211; General tandem power and press, pot's. 216; Summation of split pot., 222; Sum. of pot's in secondary s., 237; Advantage in sum. of pot. values, 227 Natural division of a., 220 Ex., 224, 225-230; N. s.; Proportionate s., 219 Need of s. the a. c., 218; Method of s., 219 Practical conditions, result of s., 243; Ex., 245 Primary and secondary splits, 219 Proportionate division of a., 230 (See Regulators); Ex., 232 INDEX 431 Splitting the air current : Quantity, Increase of, 219; Q. proportional to num- ber of splits, 243 Theoretical considerations in 8., 242 Unequal splits, illustrated, 224 Spontaneous combustion, 58 Cause of explosion, 127 Standards, Comparison of, 30 Air, hydrogen, water 30, 31 S. for gases; S. for liquids and solids, 31 Static force, 25 Steam, 82 Definition ; Saturated s. ; Su- perheated s., 82 Diagram of heat and temp. curves, 83 Steam tables (Marks and Davis), by permission of publishers, Longmans, Green & Co., 84, 85 Stone Dust (See D., Shale or s.) Stoppings, in mine ventilation, 249 Stokes alcohol lamp, 284 Sulphuric acid, 61 Symbol, Chemical, 58 S. of a molecule, 58 S's in mine ventilation, 192 Tables: Circumferences and areas of circles, 391 Conversion of compound units, 411; Conversion t.; Weights and measures, U. S. and metric, 407 Logarithms of numbers, 333 Sines and cosins, 353 Squares, cubes, s. roots, c. roots and reciprocals of numbers, 373 Tangents and cotangents, 363 Tandem circulations, 214 (See C. in mines) Temperature, 43 Absolute t. Rel. to vol. of air and gas, 18; Rel. to press, of air and gas; T., press., vol. of air and gas, 20; Abs. zero, 18; How t. is measured-two scales, 43; Table, Fahr. and centigrade scales, 44 Mean observed t. dif. alti- tudes (table), 11; Drop in t. as altidude increases above sea level (table), 12; Rel. of drop in t. to alt. (formula), 13; Aver- age t. of atmos. air col- umn (formula,) 14 Volume of air and gas, Effect of t., 17 Temperature of flame (see F., Nature and T. of) Temperature of ignition, 117 Table of t. of i. of gases, 117 Testing for gas, 295 (See Flame Caps) Making a test for gas in the mine, 306; Use of gas in- dicators (See G. 1.); Use of lamps in t. for g, (See L., Mine Safety) Theory of ventilation, 161 (See Mine V.) Thermal units, 51 (See Heat) Thermochemistry, 65 Writing a thermochemical equation, 67, 69 Thermometer scales, 43 Comparison of Fahr. and centigrade s. (table) 44 Time in estimation of velocity and power, 26 Calendar t. — Day: Solar d., Sidereal d.; Month; Year: 432 INDEX Solar y. ; Sidereal y. ; Com- mon y. ;Leap y., 401 Measurement of t. : Sun t. ; Sidereal t. ; Equation of t., Local t., Standard t., 402; Eastern t., Central t., Mountain t.; Pacific t. ; Civil t., Astronomical t., 403 Transmission of heat, 52 (See H.) Transpiration of Gases from Coal, 35 Relative velocity of t. (table), 35 Triple-entry system, 263 U Undercast, in mine ventilation, 249, 251 Units of measurement: Special u.; Compound u.; U. veloc- ity; U, work; U. power, 26, 406; Heat u., 51; Kinds of u., 397; U. of ventilating press., 177; U. resistance, 192 Valence, valency, 59 Vaporization, Evaporation, Boil- ing, 50 Effect of press, on v., 50; B. points of liquids (table; 51; V. takes place at all temp., 24, 80 Vapors and Gases, 24 (See Hygrom- etry) Definition of a v., 24 Laws of v., 80 Saturated v. press, (table), 77 V. saturates space it occupies, 80 Wt. of water v.; formulas, 79, 80; Diagram, 81 Velocity (See Air Currents, Con- ducting) Constant v., 25; Acceleration, 26 Ventilating pressure, 174 (See Mine Ventilation) Ventilation, Mine (See M. V.) Ventilation, Practical, 248 (See Air Currents, Conducting) Distribution of air, 257 (See Splitting the Air Current) Entry systems : Single, Double, Triple, 263; Multiple, e. s., 265; V. of cross-entries, 259; V. of mine stables, 260; V. of longwall workings, 256 Natural v. in slope and dip workings, 162 Plan of mine (See P. of M.) Systems of V. (see Mine V.) ; S. of mine airways, 262 Volume: Atomic or specific v; Molecular v. ; Avogadro's law of v., 29; Application of 1. of v., 64; V. of atom, unity, 64 Density and v., 29 Mass, v., density, 24 V. re abs. press., 19; re abs. temp., 18 V., press., temp., 20 Power, v., press, diagram, 185 Volatile oil flame, sensitive to gas, 288 Volatile oils, in safety lamps, (See Ilium inants for S. L.) Give fuel cap in testing for gas, 271 Light v. o., 308 Water: Density referred to air, 31; Unit wt. dif. temp, (table), 34 INDEX 433 Water column, Calculation of, 6 Water gage, The Mine, 175 Calculation from m. potential, 206 Equivalents in measurement, 175, 185; Diagram, 184 Reading the w. g., 177 Scales, Dif., 176 Use of w. g. in the mine; What it shows, 178 Water vapor (See Vapors and Gases) Weight : A property of matter, 22 Atomic w., molecular w., 59 W. of air: Formulas, 4, 79, 80; Dif. altitudes and temp. (tables), 11, 15; W. of elements (table), 28; W. of substances (table), 32; W. of water, dif. temp., 31, 33; W.of oils (table), 33; W. of woods (table) 34 Weights and measures, 397 Systems in use; Standards of weight, length, capacity, 397 Weights and measures: U. S. and British systems, 398 Calendar time, 401 Measurement of time, 402 Metric system of w. and m., 403; Metric abbrevia- tions, 406 ; Conversion tables, 406; Compound units, 411 Wet-and-dry bulb hygrometer, 72 (See H.) Whitedamp (See Carbon Monoxide) Wire gauze : Cooling effect ; Prin- ciple of w. g., Standard mesh, 269 Windy shot, in blasting, cause of explosion, 127 Wolf safety lamp, 285 ; Flame- cap diagram, 303 Wood, Wt., of dif., (table), 34 Work: Internal w. due to expansion of air or gas, calculated in two ways, 20, 21 W., in mine ventilation, syn- onymous with "power on the air," 182 YC 33742 UNIVERSITY OF CALIFORNIA LIBRARY. 