Heater, [65], [77], [79], [80], [81], [118], [119], [135], [141], [143], [196], [197]

Hectograph, [205], [206]

Hectoliter, [228]

Hectometer, [229]

Hinge, [184], [185]

Homogenizer, [180]

Horse power, [210]

Hot-water furnace, [64]

Hot-water tank, [117]

Humidity, [239]