POLENI, Giovanni.

4to, 3 leaves, pp. 65, (1), 2 leaves (licence leaf and colophon with woodcut coat-of-arms), 1 stilted engraved plate. Woodcut initials and ornaments. Original carta rustica boards (tear in top of spine), uncut, spine overlayed at an early date with marbled paper now torn and with pieces missing. Engraved bookplate of W.C. Mylne (William Chadwell Mylne, 1781–1863, engineer and architect).

FIRST EDITION. Poleni’s second work on hydraulics, with “reports on experiments on water flow and on the force exerted by an impacting fluid” (DSB). Poleni was the most prominent Italian hydraulics engineer of the early eighteenth century. “As an engineer, Poleni was a consultant in matters of water supply and flood control and an arbitrator between rulers of neighbouring states. His principal contributions to hydraulics were threefold. In his De Castellis of 1718 he cited measurements indicating the coefficient of contraction for a sharp-edges orifice to be 0.62, a considerable improvement upon Newton’s value 1/√2. He also experimented with short tubes attached to the orifice and found that a maximum rate of eflux was obtained with an intermediate length of tube” (Rouse & Ince, History of hydraulics, p. 113).