=Inspection shop=, required of the underwriters steam fire pump makers, 356 =Installation of electric pumps=, 268 =Intensifier=, hydraulic, des., 173 =Introduction, historical=, 35-70 =Introductory Considerations=, 70 =Invention of pressure engines=, a new mode of employing water as a motive agent, 147 =Inventions, successive=, 65 water lifting, 53 =Iron cases for turbine water wheels=, des. and ills., 136 =Iron draft tube=, des., 137 =Iron=, specific gravity of, 96 =Italian mode of raising water=, des. and ills., 51 =Jantu=, the historical, des. and ills., 54 =Jet pumps=, why so called, 188 =Jets=, direction of, from orifices, 113 =Joseph’s well=, Cairo, ills., 45 use of chain of pots in, 63, 64 =Joule’s experiment=, 284 =Knowles steam pump=, ills. and des., 310-312 =Knuckle-joint=, def., 20 =Laidlaw-Dunn-Gordon duplex underwriter pump=, ills. and des., 273 steam pump, ills. and des., 290-292 =Laminated pole piece=, def. and ills., 254 =Law of gravity=, 85 =Laws of falling bodies=, 86 Table, 87 =Lead=, specific gravity of, 96 “=Leakage=,” def., 24 =Leather collar hydraulics=, the invention of Bramah, 153, 154 the, of a hand pump, how held in place, 191 valve of hand pump, ills., 195 =Leffel-Samson turbine= water wheel, des. and ills., 130 =Leffel water wheel=, ills., 128, 130, 132, 134, 136, 144 =Levator=, quotation from, X “=Lift and drop of a valve=,” def., 24 =Lifting-jack=, def., 29 =Lifts and cranes, hydraulic=, 180 =Line of direction=, or line of a falling body, 88 “=Liner=,” def., 24 =Liquid=, def., 73 =Liquids=, as a condition or state of matter, 73 equilibrium of superposed, data, 81 three cases of flow under pressure, 105 veins, form and constitution of, 106, 107 =Live steam=, def., 286 “=Losing water=,” def., 25 “=Lost motion=,” def., 25 =Low pressure steam=, def., 286, 25 “=Lug=,” def., 25 =Magnetic current=, pressure necessary to produce a, 242 field of how produced, 260 needle, des., 266 ills., 242 =Magnetism=, 244 =Magneto-electricity=, 245 =Magnets, electro=, ills. and des., 259 =Magnitudes=, three-time, length and quality, 87, 88 “=Main=,” def., 25 =Manual power=, 187 =Marble=, specific gravity of, 96 =Mason, Chas. J.=, quotation from, VII =Mason steam pump=, ills. and des., 297-299 =Matter=, def., 88 solid, liquid and gaseous, states of, 73 three physical conditions, des., 73 =McGowan steam pump=, ills. and des., 308-310 =Mean gradient=, def., 25 =Measurement of water pressure=, 113 =Mercury=, specific gravity of, 96 =Mica=, specific gravity of, 96 =Mica=, where used, 251 =Millstone=, specific gravity of, 96 =Miner’s inch=, def., 25 =Mining outfit=, how divided, 275 =Mississippi River gauge cock=, def., 25 =Model= of suctions and force pumps, glass, 181