Inventors at Work, with Chapters on Discovery

by George Iles

Limbs and Lungs as Prototypes.

Long before there was a philosopher to classify levers into distinct kinds, the foot of man was affording examples of levers of the first and second orders, and his fore-arm of a lever of the third order. Ages before the crudest bagpipe was put together, the lungs by which they were to be blown, and the larynx joined to those lungs, were displaying a wind instrument of perfect model. The wrists, ankles, and vertebrae of Hooke might well have served him in designing his universal joint. Indeed weapons, tools, instruments, machines, and engines are, after all, but extensions and modified copies of the bodily organs of the inventor himself.

Lever of the 1^st order.

Lever of the 2^nd order.

Lever of the 3^rd order.

P, power. F, fulcrum. W, weight.