=Viscosity=, def., 33, 75 of fluids, des., 99, 102 =Vis viva=, def., 102 =Vitreous electricity=, 245 =Vitruvius=, quotation from, 57 =Volt=, def., 256 =Voltaic electricity=, 246 =Voltmeters=, def., 256 =V thread=, def., 33 =Washer=, def., 33 =Waste channel of water-falls=, 119 =Waste pipe=, sizes for the underwriter pump, 384 =Water and steam=, one an elastic and the other a non-elastic liquid, 149 =Water arch=, def., 33 =Water as an example of a fluid=, 73 =Water-bellows=, def., 33 =Water, boiling point of=, 76 cap, def., 33 chemical composition of, 75 clocks, des. and ills., 39 conditions of, 75-77 considered from a chemical standpoint, 75 data relating to, 75 =Water dust=, French term for steam, 285 end, def., 33 of the underwriter steam fire pump, ills. and des., 367-380 pumps, des. and ills., 209 =Waterfalls=, des. of supply and waste channels, 119 division of parts deriving energy, 119 =Water, flow of, result of gravity=, 89 four notable temperatures of, 75 =Water-hammer=, def., 34 or valve slam, def., 374 influence of gravity on weight of, note, 80 =Water-lifting inventions=, 53-70 of what composed, 285 practically non-elastic, data, 75-77 pressure engines, care of, to prevent freezing, etc., 145, 146 =Water pressure machines=, 117-154 measurement of, 113 due to its weight, data, 83 pressure of, table, 114 pressure on column of, data, 77 how transmitted, data and ills., 79 proportioned to its depth, data, 83 table, 77 =Water pressure or hydraulic motors=, des., 147 =Water pumps=, why so called, 187 racks for turbine wheels, how best made, 131 =Water ram=, def., 34 rises to same level in opposite arms of tube, data, 83 salt, boiling point of, 76 sea, how many cubic feet to ton, 97 tables of weight and volume, etc., 76 temperature of, for calculations, 75 =Water=, theoretical and actual flow, note, 106 three laws of frictional resistance of, 100 =Water-tight turbine=, ills. and des., 139 under pressure, efflux of, 105-113 velocity of, in flumes and pipes, rule, 138 tail race, rule, 138 weight and volume of, tables, 76, 77 in round numbers, 76 one cubic foot of, 76 =Water wheel=, 132, 133 =Water wheels=, 119-144 des. and ills. of “chutes,” gate-seats, “gates” and “buckets” of turbine, des. and ills., 139 des. and ills. of flutter wheels, etc., 121-125 des. of “runners,” “guides” and water racks, 130 des. of the “step” buckets, etc., 130 des. “tail water” and “draft tube”, 135 setting of, in penstock, 134 Leffel, 130 when the water is measured, 130 =Water will rise as high as its source=, data, 83 =Watt, Jas., account of his discovery= of the properties of steam, 280, 281 =Watt, Jas.=, historical, ref., 35 =Weinman steam pump=, ills. and des., 322-324