THE INDEX 



533 



Nitroglycerin, 174, 175 f., 177, 178 

 North: errors in finding true, 25, 



26; exact determination of, 27; 



methods of determining, 24.fr.; 



variation of compass from true, 



26 

 North Star, 23; for determining 



direction, 24 

 Notebooks, how to keep, 1, 2 



Oak, 106, 121 f., 124, 126, 164, 229 



Offsets, 90, 92 



Ohio Agricultural Experiment Sta- 

 tion, 228 



Oil: for gas-engine cooling, 519; 

 for heating purposes, 419; for 

 preserving wood fence posts, 

 229; for road covering, 207 



Oil gas: Blau-, 425 f.; for light- 

 ing, 424 ff . ; cracking point of, 

 425; Pintsch, 425 



Osage orange for fences, 223 f., 

 242 



Oshkosh, Wis., rainfall statistics 

 for, 251 



Outcenter, 514 



Over-irrigation, 264 



Oxygen, use in gunpowder, 73 f. 



Pace, 11 



Pacing, 11 ; source of errors in, 12 



Paint: bases, 167 f.; cement, 170; 

 cold-water, 169; coloring mat- 

 ter for, 169; covering capacity 

 of, 319; driers, 168 f.; for 

 inside work, 169; ready-mixed, 

 169; solvents, 168; vehicles, 

 168 



Painting: exterior, 317 f. ; interior, 



3 18 

 Paper: for insulating material, 



160; for wall covering, 167 

 Parallelogram, formula for area 



of, 17 

 Parallels : curvature corrections 



by, in land surveys, 87, 89; 



standard, 89 

 Pavements, 207 ff. ; bituminous, 



208 f.; block, 208; Portland 



cement concrete, 209 

 Pelton wheel, 491 

 Pencils for records, 2 f . 

 "Penny," as applied to nails, 161 

 Perch, 9 



Percolation and disposal of rain- 

 fall, 76, 78 

 Petroleum, for preserving wood 



posts, 228 

 Pied du roi, 10 



Pine, 106, 120, 123, 126, 299 

 Pinion, 472 

 Pintsch gas, 425 



Piping for water systems, 372 ff . ; 

 drainage fittings for, 374 f. ; 

 fixtures for home, 375 ff. ; fric- 

 tion of water in, 373; table of 

 size, weights, and cost of, 373 

 Pitch pockets, 112 

 Pith, 112 

 Pitman rod, 472 

 Plant growth, 76, 80. See also 



Crop production 

 Plaster, 166 f.; substitutes for, 



167 

 Plaster board, 316 

 Plaster work, 317 

 Plowing by means of tractors, 



484.fi. 

 Plus, 10 

 Pneumatic system of pumping 



water, 371 

 Pole, 9 



Poplar, 106, 123, 126 

 Poppet valve, 51 -'. f. 

 Porches, 328 

 Portland cement. See Cement; 



Concrete 

 Pound, 17 

 Power, 462; motive, 478-492; 



water, 490 ff. 

 Power, transmission of, 466 ff . ; 



by belting, 467 ff. ; by chain- 



and-sprocket, 469; by gearing 



{see Gearing) ; by pulleys, 466 f . ; 



by shafting, 466 ff . 

 Power, N. D., rainfall data for, 77 

 Preservatives for fence posts, 



228 f. 

 Presto-lite, 427 

 Primer, 179 



Principles of machines, 461-477 

 Puddling of soil for road building, 



214 

 Pulleys, 466 f . 



Pump, 369, 371 ; cylinders for, 366 

 Pumps, force, 366; lift, 366 



Quarter-sawing, no 



