The Century of Inventions of the Marquis of Worcester / from the Original MS., with Historical and Explanatory Notes and a Biographical Memoir

by Marquis of Edward Somerset Worcester

No. XXIV.

How to increase the strength of a spring to such a degree as to shoot bombasses and bullets of an hundred pound weight a steeple height, and a quarter of a mile off and more, stone bow-wise, admirable for fire-works and astonishing of besieged cities, when, without warning given by noise, they find themselves so forcibly and dangerously surprised.

NOTE.

The strength of a compound spring formed of two metals may, by the application of heat, be increased to any given power. Rationale.—Iron possessing an expansive power of 1/95, and brass being only 1/60, the weaker metal will be bent by that whose power of expansion is greater, and the impulse of the spring increased in an equal ratio.