=Duplex fire pump=, shop name and shop number required on plate attached to underwriters, 355 underwriters steam end, 356-366 =oil pumps=, ills. and des., 339 power pump not to be confounded with “Duplex pumps”, 230 pump, ills. and des., 331-398 outside packed plunger pattern for high pressure, 341 setting valves of, 338 pumps, history of, 65, 69 only acceptable for fire pumps, 351 with Deane switch valve, 343 Worthington admiralty pattern of, ills. and des., 337 steam fire pump, underwriters, water end of, 367-380 steam pump, important note, 333 valve motion, 333-334 underwriters steam, fire pump, 343-398 “=Dutchman=,” def., 21 =“Duty” of pumps=, def., 20 =Dynamics=, def., 245 =Dynamo=, def., 247 early Edison type, 248 electric current from a, how reversed, 264 five principal parts, 247 when it becomes a motor, 260 =Dynamometer=, turbine, des., 128 =Eccentrics of the triplex power pump=, how set, 232 =Edison dynamo=, early type, 248 =Efficiency of an electric pump=, 268 =Efflux of water= under pressure, 105-113 =Elbow=, def., 21 shown in piping, ills. and des., 223 =Electric circuit breakers=, 255 =Electric current=, action of, 257 from a dynamo, how reversed, 264 =Electric drive for fire pumps=, ills. and des., 273 house tank pumping plant, ills. and des., 269 =Electricity and electrical machinery=, 243 how classified and defined, 244 how measured, 246 important note, 243 in vibration, 244 vitreous, negative, positive, etc., 245 whence derived, 243 =Electric mining pumps=, ills. and des., 274-276 =Electric motor and air pump=, ills. and des., 271 motor, des., 249 operating a portable track pump, ills. and des., 276 pump, ills. and des., 272-273 pump, 241-276 pumping installation, notable example, 275 pumping machinery, 267-276 pumps, care and management, 268 properly power pumps, 208 why so called, 187 =Electric-rheostat=, transformer, compensator, 256 =Electric-switches and switchboards=, 254-255 =Electro-magnets=, ills. and des., 259 =Electro-motive force=, def., 246 =Elementary hydraulics=, 71-73 =Elements, phial of four=, (mercury, water, alcohol and petroleum) des., 81 =Elevator pumps=, why so called, 187 =Emery=, specific gravity of, 96 =E. M. F.=, def., 246 =Energy=, mechanical and electrical, how transformed, 260 =Engineering=, as a branch of hydraulics, 74 =Engine, Rife hydraulic=, 177-179 =English unit of heat=, ills. and des., 284 =Equilibrium of superposed liquids=, data, 81 =Equilibrium-valve=, def., 21 =Ewbank, Thomas=, author, ref. to, 46 “=Ewbank’s hydraulics=,” credit given for use of, 52 =Ewers, golden=, used by rich Egyptians, 38 =Expansion joint=, des., 21 =Face=, def., 21 =Factor of safety=, def., 22 =Feather, or sunk key=, def., 22