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two remarkable eccentrics, Robert Boyle and Sir Kenelm Digby. A little later on, "these divers worthy persons inquisitive into natural philosophy and other parts of human learning did by agreements meet weekly in London on a certain day to treat and discourse of such affairs." In its early days the Society was known as the 'Invisible College," and before 1660 it seems to have had a regular habitat at Gresham College in Bishopsgate Street, where Wren was Professor of Astronomy. In 1659 the worthy John Evelyn began to take keen interest in the proceeding. Wallis records that the subjects discoursed of were "the circulation of the blood; the valves in the veins; the venal lactea; the lymphatic vessels; the Copernican Hypothesis; the nature of comets and new stars; the satellites of Jupiter, the oval shape of Saturn, the spots in the sun, and its turning on its own axis; inequalities and selenography of the Moon; the several phases of Venus and Mercury; the improvement of telescopes and grinding of glasses for that purpose; the weight of air, the possibility or the impossibilities of vacuities, and Nature's abhorrence thereof; the Torricellian Experiment in quicksilver; the descent of heavy bodies, and the degrees of acceleration thereof; and divers other things of like nature." The Records of the Society begin on November 28th, 1660.