A Table of the Rarefication of the Air: Using a glass U - tube and a column of mercury, the volume of air contained in one arm of the tube increased as the length, and so the pressure, of the column of mercury in the other arm was reduced. The change in volume was in accord with the theoretical law, Boyle's Law, that volume is inversely proportional to the pressure. Page from "New Experiments Physico - Mechanical, touching The Spring of the Air" by Robert Boyle (London, 1682). Robert Boyle (1627 - 1691) Irish born chemist and physicist