Helical teeth, cutting in the lathe, [i, 69].

Herring-bone gear-teeth, [i, 69].

Hexagon gauge, [i, 381].

Hide, parts of, used for belting, [ii, 208].

High pressure steam engine, [ii, 372].

High speed automatic engines, [ii, 427].

Hobbing dies, methods of, [i, 473].

Hob for threading dies, [i, 474].

Hobs and their uses, [i, 335].
for cutting up dies, [i, 99].
threading dies, [i, 474].

Hoe, [ii, 369].