Entered in the undated manuscript catalogue in the next chapter, Geometry, with the price, 33.0.

On October 10, 1815, after the delivery of his library to Congress, Jefferson wrote to George Watterston, the Librarian: “ It was sometimes my practice, when reading on a subject to make notes on a separate paper, and to stick the paper loosely into the book to which it related, as the most convenient place for finding it again. in one of the volumes of Bezout’s cours de Mathematiques, you will find such a note on the method of taking inaccessible heights and of reducing the planes of the triangles, when inclined, to the plane of the horison. I believe it is in Bezout’s course for the artillery, tho possibly in that for the Marine, for they are distinct works. it is on one or two leaves of 8 ^vo. size. preparing soon to undertake an operation of this kind on the ground, I should be very glad to recover that paper of notes, to refresh my memory on the subject. You would greatly oblige me by turning to the book and withdrawing the paper, which is loose, and inclosing it to me by return of the mail . . .”

Watterston replied on October 13: “I had the honor to receive your letter of the 10th inst: yesterday evening, requesting the transmission of your MS notes, contained in Bezout. I am happy to have it in my power to comply with your request, by enclosing & forwarding them to you--In the book refered to I find three half sheets carefully fastened between the printed pages, one of which (the one I presume you require) I have taken out & enclose; the other two relate to plane & spherical trigonometry & the solution of oblique angled triangles & that of right angled spherical triangles. If you should desire either of these two, by making known to me that desire, I will cheerfully transmit them to you . . .”

On October 20, Jefferson wrote to Watterston: “ I thank you, Sir, for the paper you have been so kind as to return me from Bezout. it was nothing more than an exemplification of the process prescribed in his book. the other leaf or leaves inserted therein are not desired. they were inserted as a supplement to his spherical trigonometry, because he omits (as nearly all French Mathematicians do) L ^d. Nepier’s catholic canon, which is of great value, as supplying the many rules in that branch by a single one, easily retained in the memory. I inserted the same in Potter’s mathematics, because he has given L ^d. Nepier’s canon unintelligibly & incorrectly . . . ”

In a letter dated from Monticello, June 6, 1807, concerning the mathematical studies of his grandson, Francis Eppes, Jefferson wrote to J. W. Eppes, the boy’s father: “ . . . but with Bezout (which you possess) I do not think he [i.e. Francis Eppes] will need the aid of an instructor. that author is so remarkably plain that anyone may teach himself by his aid . . .”

Étienne Bezout, 1730-1783, was a native of Nemours, where a statue of him was erected in 1885.