Scales, [98], [225]

Screw, [243]

Sea-breeze, [283]

See-saw, a lever, [228]

Sensation, influence of the conduction of heat on, [310]

Shape, relation of, to velocity, [195]

Shot, manufacture of, [60]

Signal key, [415]

Silk-worm, thread of, [19]

Size limited by gravity, [90]