Radius of gyration, 21 
Rafters, 201 
Rail bearers, 242 
Railway brakes, 346 
Railway bridge floors, 242 
Rankine-Gordon formula for struts, 166 
Ratchets, 408 
Rate of work, 26 
Ratio, Poisson’s, 155 
Reaction of jet, 479 
Reaction turbines, 493 
Reciprocal figures, 37 
Reciprocating parts, inertia of, 315 
Rectangular notches, 451 
Rectilinear motion, 15 
Reinforced concrete beams, 109 
Relations between bending moment 
and shearing force diagrams, 92 
Relations between ¢, E, OC, and K, 156 
Relative motion, 15 
Renold’s chain, 371 
Resilience, 69 
Resilience of a beam, 132 
Resolution of forces, 34 
Resolution of velocities and accelera- 
tions, 17 
Rest and motion, 15 
Resultant moment of a system of forces, 
43 
Resultant pressure, 433 
Resultant vector, 13 
Retardation, 16 
Reversal of shearing stress in beams, 
100 - 
Reversed efficiency of a machine, 27 
Reversible ratchets, 409 
Reverted wheel trains, 391 
Revolving pendulum, 329 
Revolving vane, action of jet on, 482 
Rigidity, coefficient of, 66 
Rims of pulleys, 365 
lubrication, 274 
Ring, strength of, 154 
Riveted joints, 72 . 
Riveting in booms, 235 
Riveting of plate girders, 220 
Rolled joists, 214 
Roller for cylindrical cam, 402 
Roller, fracture of, 176 
Rollers, crushing tests on, 189 (Ex. 8 
Rolling load, 93 
Roof coverings, 204 
Roof coverings, weight of, 210 
Roof trusses, details of, 205-210 
Roofs and roof trusses, 201 et seq. 
Root circle, 376 
Rope brake dynamometer, 351 
Rope pulley, 366 
Ro motion, 15 
Rotating cams, 399 
Rotating guides for sliding piece, 275 
Rotational inertia, 21 
Rupture, modulus of, 109 
INDEX 549 
Safety, factor of, 68 
Saw-tooth truss, 202 
Scalar quantities, 12 
Schiele’s pivot, 267 
Scotch turbine, 492 
Screw-jack, 279 (Ex. 14) 
Screws, efficiency of, 264 
Screws, friction of, 262 
Secondary bracing, 201, 236 
Section modulus figures, 105 
Sections, method of, 196 
Sensitiveness of governors, 335 
Series, 3 
Shaft, angle of twist of, 80 
Shaft, moment of resistance to torsion, 
81 
Shafts, formule for, 82 
Sharp-edged orifices, flow through, 447 
Shear stress equivalent to two normal 
stresses, 140 
Shear stresses in beams, 148 
Shear stresses on planes at right angles, 
equality of, 139 
Shearing by forces in different planes, 
101 
Shearing force at concentrated load, 91 
Shearing force diagrams, 59, 88 
Shearing forces on beams, 87 
Shearing, positive and negative, 88 
Shearing strain, 64, 65 
Shearing strength of materials, 187 
Shearing stress, 64, 65 
Shock, 69 
Silent ratchet, 410 
Simple conical pendulum governor, 332 
Simple harmonic motion, 296 
Simple pendulum, 299 
Simple strains and stresses, 64 et seq. 
Simple torsion, 79 
Slates, 204 
Sleepers, 244 
Slider acceleration, 301 
Sliding cams, 398 
Slider-crank chain, 308 
Slider velocity diagrams, 300 
Sliding friction, 260 
Sliding keys, friction of, 275 
Slope of bent beam, 114 
Soaking, 182 
Space average and time average of a - 
force, 284 
Speed, 15 
Spherical shells, thin, 76 
Splash lubrication, 275 
Springs, helical, 83 
Statical friction, 260 
Statics, 1 
Steam pumps, direct driven, 509 
Step pulleys, 364 
ee pe teeth, 386 
Stiffeners, web, 219 
Stiffness of a beam, 115 
Strain, 64 
