WALLIS, John (1616-1703). A Discourse of Gravity and Gravitation, grounded on Experimental Observations: Presented to the Royal Society, November 12. 1674. London: John Martyn for the Royal Society, 1675.

First edition of Wallis’s response to Sir Mathew Hale’s critique of Boyle’s experiments on the weight and spring of air, and part of Wallis’s project to provide the mathematical basis of mechanics. Hale had published two books criticizing Boyle's barometric experiments, and Wallis was commissioned to respond to the attacks. His discourse was presented to the Royal Society in November 1674 and printed for them the following January. Wallis begins by setting out his mathematical approach to the laws of motion, stating that it is not his intent to discuss the causes or nature of gravity, but rather to give as precise as possible a mathematical description of gravity and related phenomena. He then embarks on a detailed critique of Hale’s "explanations," which are rooted in philosophy and not in quantitative analysis. Wing W574.

Quarto (200 x 154mm). Royal Society Imprimatur leaf, folding engraved plate (a little dustsoiled at end with small chip to top edge of final leaf). Later plain wrappers, red edges.