Resistance, moment of, 153.

Resolution of forces, 47.

Rigid arches, 308.

S.

454.

Sandstone, weight of, 9, 407.
Screw-piles, 421-423.

stresses in webs of plate-
girders, 418, 427-430.

Sheer-legs, 300, 471.

Shoes of principals, 351.
Side pressure on bridges, 413.
Slates for roofs, 355.
Snow, weight of, 347.

Steel, Admiralty tests for, 38, 39.
advantages of, for bridge
work, 37.

annealing, 40.

Board of Trade rules for, 418.
buckled plates, strength of,

439.

strength of, 471, 472.

crushing strength of, 37.

elasticity of, 38.

flooring plates, 435, 439-443.

Lloyd's rules for ship-plates,
39.

rivets, strength of, 377.
rolled joists, strength of, 186.
shearing strength of, 37.
tensile strength of, 37-41, 486.
treatment of, by hydraulic
pressure, 40.

443.

wire, strength of, 453.
working stresses in, 418.
Stiffeners to webs of plate-girders,
428.
Stiffening suspension bridges, 454.
Strains, different kinds of, 2-5.
Stresses, different kinds of, 2-5.
internal, in beams, theory

of, 151.
measurement of. 3.
on braced piers, 467.
working, in cast-iron, 196,

416.

in chains, 474.
in steel, 418.

in timber, 419.
in wrought-iron,
417, 418.

Struts, long, 7. See also "Columns."

Suspension bridges, advantages and

foundations, 419.

roofs, 363-365.

disadvantages
of, 453.
attachment

of

chains to piers,

446.
stiffening, 454.
stress-diagrams
of, 444, 450.
suspending-rods
of, stresses on,
448.

with sloping sus-

pension - rods,

448.

Tee struts, strength of, 209-212.

U.

Ultimate strength, 16.
Under bridges, dimensions of, 405.
Unit-stress, 3.

V.

W.