474 



INDEX 



Levers Continued 



moment of forces, 27 



principle of, 26 



second class, 29 



shapes of, 32 



third class, 30 

 Ley den jar, 184 

 Light, 113-120 



and color, 1.19 



arc lamp, 117 



characteristics of , 113 



Drummond, 117 



gas, 118 



importance of proper, 115 



incandescent lamps, 116 



Nernst lamp, 117 



reflected, 113 



refracted, 114 



standard of, 115 

 Lightning, 186-189 



cause of thunder, 188 



danger from, 187 



forms of, 187 



rod, 188 



Line of direction, 56 

 Liquids, 



capacity of pipes, 73 



hydraulic press, 71 

 use of, 72 



mechanics of > 68-85 



pressure, 69-70 



properties of, 68 



use in industry, 68 

 Lubricants, 



greases, 152 



object of, 152 



oils, 152 



requirements of good, 154 



solid, 153 



Machines, 

 and tools, 22 

 centrifugal, 60 



classification of. 421 

 cutting capacity of. 422 

 cutting metal, 423 ' 

 drilling, 428, 433 

 grinding, 435 

 key-way, 432 

 lathes, 423-420 



measurement of work for, 419 



mechanical principles of, 22-25 



milling 433-435 



molding, 387 



planer, 429 



power, measurement of, 47 



power press, 435 



screw, 427 



shaper, 429, 431 



why used, 22 

 Machine-shop, 418-440 



tools, 421 



trades, 



division of, 438 

 Machinists, work of, 418 

 Magnetic field, 190 

 Magnetism, 



and electricity, 167-183 



magnetic field, 167 



nature of, 167 

 Magnets, shape of, 167 

 Malleability, 4 



table of, 5 



Manufactured gas, 118 

 Mariner's compass, 168 

 Mass, 10 

 Match, 385 



plate, 386 

 Materials, 



strength of, 233-248 (See also 

 "Strength of materials") 



weights of, 388 

 Matter, 



indestructibility of, 5 



properties of, 1-6 



three states of, 86 

 Measure, 7-21 



coiled belting, 287 



electrical units of, 172 



of distance, 8 



of electric power, 173 



of screw thread, 253 



of stresses, 237 



precision of, 17 



table of, 12 



units of, 7 

 Mechanical advantage, 26 



cost of, 49 



Mechanical drawing supplies, 225- 

 232 



blue-print paper, 231 



drawing paper, 22,7 



