  The third edition appeared in 1726, thirty nine years after the first. Most changes in it involved either refinements or new data. The most significant revision of substance was to the variation of surface gravity with latitude, where Newton now concluded that the data showed that the Earth has a uniform density. Subsequent editions and translations have been based on the third edition. Of particular note is the edition published by two Jesuits, Le Seur and Jacquier, in 1739-42, for it contains proposition-by-proposition commentary, much of it employing the Leibnizian calculus, that extends to roughly the same length as Newton's text.