Note 159 — BOOK II. AN ACCOUNT OF THE WORLD AND THE ELEMENTS.
John Bostock translation
For the periodical revolution of Mercury see note142, p. 27. Its greatest elongation, according to Playfair, p. 160, is 28°. Mrs. Somerville, p. 386, states it to be 28° 8′. Ptolemy supposed it to be 26·5 degrees; Almagest, ix. 7. We learn from Hardouin, Lemaire, i. 246, that there is considerable variation in the MSS. with respect to the greatest elongation of Mercury.