April 11 1754.1
Some thing’s observed concerning gravity, which encreases as you approach the Center of the earth in a reciprocal proportion of the squares of the distances, and under this head were introduced pendula and we saw that all pendula of equall length oscilated in equal time whether the arches they described were greater or less. We were also inform’d that bodys falling in Chords of a Circle will fall in equal times Caeteris paribus; and in the same time that the same Body would pass through the diameter, as
1. JA’s notes on Winthrop’s course of lectures end with this entry, for the very good reason that Winthrop broke off his course this year with the eighth lecture in order to travel to Philadelphia, where he met his fellow scientist and correspondent Benjamin Franklin for the first time. His trip kept him away from Cambridge from 15 April to 24 May. See his MS Diary for 1754 (MH-Ar); also Sibley-Shipton, Harvard Graduates, description begins John Langdon Sibley and Clifford K. Shipton, Biographical Sketches of Graduates of Harvard University, in Cambridge, Massachusetts, Cambridge and Boston, 1873– . description ends 9:246–247.
The present entry also ends JA’s efforts (so far as we know) to keep a diary as a Harvard student, although he was not graduated until July 1755. As explained in the Introduction, an interval of more than four years passed before he made further use of the folio MS designated as the Diary Fragment. When, in Oct. 1758, he did so—having already begun in Nov. 1755 a diary record in pocket form—he used the MS for different and very miscellaneous purposes rather than as, strictly speaking, a diary; see the following entries.