Against Chandrasekhar's interpretation of Newton's treatment of the precession of the equinoxes (Q1296230)

In his book `Newton's Principia for the common reader' (1995; Zbl 0821.01012), \textit{Subrahmanyan Chandrasekhar} claims that Newton, in his treatment of the precession of the equinoxes, anticipated certain ideas of rigid body dynamics. According to the author of the present article, this claim is not justified. In a critical analysis of Chandrasekhar's text about Newton's treatment of the precession of the equinoxes, Dobson comes to the conclusion that Chandrasekhar misunderstood Newton's meaning, and that the Principia contains no satisfactory method for dealing with the rotational motion of extended bodies. In an appendix of 6 pages, the author proves by a modern method the result that Newton obtained in Lemmas 1 and 2 of Book III of the Principia.