“=Modulus=” of a steam pump, def., 25 =Momenta=, equal, principle of applied to fluids, 83 =Montgolfier’s hydraulic ram=, note, 175 =Moore steam pump=, ills. and des., 313-315 =Motor=, alternating induction, des. and ills., 252 and centrifugal pump, ills. and des., 272 direct current, des., 249 electric, and air pump, ills. and des., 271 electric, des., 249 electric, why revolves, explanation, 258 =Motors=, division of water, des., 119 giving names to pumps, 187 hydraulic, 147, 153 induction, as used in mines, 275 =Motor=, water, simplicity of, 120 note, 120 when it becomes a dynamo, 260 =Mud, pump for handling=, ills. and des., 233 =National standard duplex fire pump=, ills. and des., 343-398 points of difference between it and the trade pump, 395 pump, 349 specifications for the manufacture of steam fire pumps, 349, 351 =National steam pump=, ills. and des., 303, 304 =Natural philosophy=, hydro-mechanics as a branch of, 74 =Needle, magnetic=, des., 266 ills., 242 =Negative electricity=, 245 =Newcomen pumping engines=, history of, 65 Thomas, historical ref., 36 =Niagara Falls turbine wheels=, notes, 142, 143 des. and ills., 140, 144 =Nipple=, def., 26 =Nitrogen=, what part of air, 15 =Noria=, the, or Egyptian wheel, des. and ills., 57 =Nozzles=, kind of, to be used in connections with the national steam fire pump, 353 =Oak=, specific gravity of, 96 =Oil pump=, ills. and des., 233 duplex, ills. and des., 339 =Olive oil=, specific gravity of, 96 =Oscillating pumps=, why so called, 188 =Outboard delivery pipe=, def., 26 =“Outfit” of underwriter pump=, 273 =“Out-put” of electric motor=, 249 =Over-shot water wheel=, des. and ills., 123, 125 =Oxygen=, what part of air, 15 =Packings, hydraulic=, 153, 154 most suitable for power pumps, 230 =Packing of hand pumps=, 204 loss of power in use of hydraulic, 154 =Parts of a pump=, 209 =Parts of pitcher pump=, ills. and des., 195 =Penstock=, ills., 134, 135 def., 26 =Persian wheel=, des. and ills., 58 =Pet-cock=, def., 26 =Pewter=, specific gravity of, 96 =Picotah of Hindostan=, des. and ills., 49 =Pine=, specific gravity of, 96 =Piston=, actual velocity of, 374 =Piston= and valve rods of the underwriter fire pump, ills. and des., 364 =Pistons, steam=, of the underwriter steam fire pumps, 359 =Piston=, the, is nucleus of power of pumps and engines, 149 =Pitcher pump=, def., 26 spout pump, des. and ills., 195 =“Pitman” of a pump=, des., 190 =Pipe-clamp=, def., 26 =Pipe sizes, table of=, for underwriter pump, 380 “=Pipette=,” def., 26 =Piping a pump=, ills. and des., 222, 223 =Pipkin=, ills., 35 =Phial of four elements= (mercury, water, alcohol and petroleum), des., 81 =Phosphorus=, specific gravity of, 96