SIR,--I have duly received your favor of the 14th, with a copy of your mathematical principles of natural philosophy, which I have looked into with all the attention which the rust of age and long continued avocations of a very different character permit me to exercise. I think them entirely worthy of approbation, both as to matter and method, and for their brevity as a text book; and I remark particularly the clearness and precision with which the propositions are enounced, and, in the demonstrations, the easy form in which ideas are presented to the mind, so as to be almost intuitive and self-evident. Of Cavallo's book, which you say you are enjoined to teach, I have no knowledge, having never seen it; but its character is, I think, that of mere mediocrity; and, from my personal acquaintance with the man, I should expect no more. He was heavy, capable enough of understanding what he read, and with memory to retain it, but without the talent of digestion or improvement. But, indeed, the English generally have been very stationary in latter times, and the French, on the contrary, so active and successful, particularly in preparing elementary books, in the mathematical and natural sciences, that those who wish for instruction, without caring from what nation they get it, resort universally to the latter language. Besides the earlier and invaluable works of Euler and Bezont, we have latterly that of Lacroix in mathematics, of Legendre in geometry, Lavoisier in chemistry, the elementary works of Haüy in physics, Biot in experimental physics and physical astronomy, Dumeril in natural history, to say nothing of many detached essays of Monge and others, and the transcendent labors of Laplace, and I am informed, by a highly instructed person recently from Cambridge, that the mathematicians of that institution, sensible of being in the rear of those of the continent, and ascribing the cause much to their too long-continued preference of the geometrical over the analytical methods, which the French have so much cultivated and improved, have now adopted the latter; and that they have also given up the fluxionary, for the differential calculus. To confine a school, therefore, to the obsolete work of Cavallo, is to shut out all advances in the physical sciences which have been so great in latter times. I am glad, however, to learn from your work, and to expect from those it promised in succession, which will doubtless be of equal grade, that so good a course of instruction is pursued in William and Mary. It is very long since I have had any information of the state of education in that seminary, to which, as my _alma mater_, my attachment has been ever sincere, although not exclusive. When that college was located at the middle plantation in 1693, Charles city was a frontier county, and there were no inhabitants above the falls of the rivers, sixty miles only higher up. It was, therefore, a position, nearly central to the