Diary of John Quincy Adams, volume 2
1786-11-08
Mr. Williams gave a public astronomical lecture this afternoon, relating to the different theory's of the planetary System; he gave an account of the Ptolemean, the Tychonic,1 and the Copernican. There was little more than what may be found in most astronomical books; but the lecture was entertaining and was 123very à propos, as it relates to the public course, and, to the book, which we have just begun to study.
Weather very comfortable.
A via media between the Ptolemaic and Copernican systems, devised by the 16th-century Dutch astronomer Tycho Brahe, who believed that five planets rotated about the sun, which in turn circled around the immobile earth.