INDEX 



313 



Power transmitted by circular shafts, 



114. 



Principal axes, 39. 

 Principal stresses, 24. 

 Principle of least work, 96, 176. 

 Puzzolan cement, 248. 



Radius of gyration, 40. 



Kankine's formula, 104, 105. 



Rate of apply ing load, effect on strength 



of cement, 251. 



Rattler test of paving brick, 280. 

 Reactions of supports, 47, 50, 51, 52, 53, 



80, 91. 



Rectangular plates, 142. 

 Rectangular shafts in torsion, 118. 

 Red cedar, strength of, 290. 

 Red fir, strength of, 290, 295, 296. 

 Reduction of area of cross section, 14, 



223. 

 Reenforced concrete, 263. 



adhesion of reenforcement, 264. 



area of reenforcement, 264. 



beams, 266, 267, 268, 269, 270. 



corrosion of inetal reenforcement, 

 263. 



object of reenforcement, 263. 



other uses of, 271. 

 Relation between stress components, 20. 



elastic constants, 30. 



shear and bending moment, 53. 

 Resilience, defined, 84. 



of circular shafts, 117. 



modulus of, 84, 226. 

 Result of straight-line law, 35. 

 Retaining walls, angle of repose, 197. 



bearing power of piles, 198. 



bearing power of soils, 195. 



column footings, 203. 



formulas for, 209. 



maximum earth pressure, 205. 



ordinary foundations, 201. 



thickness of, 212. 



Wellington's formula, 200. 

 Rope, 298. 



hemp, 302 



Manila, 302, 303. 



sisal, 303. 



wire, 298, 300, 301, 302. 

 Rubber belting, 305. 

 Rupture, modulus of. See Modulus of 

 rupture. 



Safety, factors of, 16. 

 Sandstone, formation and properties of 

 273. 



strength of, 274, 275. 

 Sapwood and heartwood, 283. 

 Seconds, timber, 295. 

 Section modulus, 38. 

 Selects, timber, 295. 

 Setting, time of (cement), 249, 250. 

 Shear, defined, 3. 



and bending moment, relation be- 

 tween, 53. 



influence line for, 88. 



maximum, 25. 



modulus of elasticity of, 18. 



simple, 27. 



vertical reactions and, 47. 

 Shearing strength of materials, average 



values, 19. 



Shearing tests, 288, 290, 292. 

 Silicon in iron and steel, 232, 240. 

 Simple shear, 27. 

 Sisal rope, 303. 



Size, effect of size of test piece on 

 strength of steel, 224. 



of timber, 296. 

 Slag cement, 248. 

 Slippery elm, strength of, 290. 

 Soundness test for cements, 248. 

 Sour gum, strength of, 290. 

 Specifications, for cast iron, 237. 



for cement, 253. 



for steel, 244. 



for wrought iron, 244. 

 Speed of application of load, effect on 



strength of cement, 251. 

 Spheres and cylinders, 122, 123. 

 Springs, helical, 119. 



hooks and links, 145. 



plane spiral, 157. 

 Spruce, strength of, 292. 

 Square plates, 141. 

 Square shafts in torsion, 118. 

 Stability, of abutments, 181. 



of arches, 172. 



or retaining walls, 210. 



Winkler's criterion for, 177. 

 Standard forms of test specimens, 244. 

 Steel, manufacture and properties, 238. 



Bessemer process, 239. 



castings, 241, 242, 243. 



impurities in, 239, 240. 



