I received, at the same time, the Abbé Rochon's pamphlets and book on his application of the double refraction of the Iceland Spath to the measure of small angles. I was intimate with him in France, and had received there, in many conversations, explanations of what is contained in these sheets. I possess, too, one of his lunettes which he had given to Dr. Franklin, and which came to me through Mr. Hopkinson. You are therefore probably acquainted with it. The graduated bar on each side is 12 inches long. The one extending to 37´ of angle, the other to 3,438 diameter in distance of the object viewed. On so large a scale of graduation, a nonias might distinctly enough sub-divide the divisions of 10´´ to 10´´ each; which is certainly a great degree of precision. But not possessing the common micrometer of two semi-lenses, I am not able to judge of their comparative merit. * * * * * TO MR. ADAMS. MONTICELLO, December 28, 1812. DEAR SIR,--An absence of five or six weeks, on a journey I take three or four times a year, must apologize for my late acknowledgment of your favor of October 12th. After getting through the mass of business which generally accumulates during my absence, my first attention has been bestowed on the subject of your letter. I turned to the passages you refer to in Hutchinson and Winthrop, and with the aid of their dates, I examined our historians to see if Wollaston's migration to this State was noticed by them. It happens, unluckily, that Smith and Stith, who alone of them go into minute facts, bring their histories, the former only to 1623, and the latter to 1624. Wollaston's arrival in Massachusetts was in 1625, and his removal to this State was "some time" after. Beverly & Keith, who came lower down, are nearly superficial, giving nothing but those general facts which every one knew as well as themselves. If our public records of that date were not among those destroyed by the British on their invasion of this State, they may possibly have noticed Wollaston. What I possessed in this way have been given out to two gentlemen, the one engaged in writing our history, the other in collecting our ancient laws; so that none of these resources are at present accessible to me. Recollecting that Nathaniel Morton, in his New England memorial, gives with minuteness the early annals of the colony of New Plymouth, and occasionally interweaves the occurrences of that on Massachusetts Bay, I recurred to him, and under the year 1628, I find he notices both Wollaston and Thomas Morton, and gives with respect to both, some details which are not in Hutchinson or Winthrop. As you do not refer to him, and so possibly may not have his book, I will transcribe from it the entire passage, which will prove at least my desire to gratify your curiosity as far as the materials within my power will enable me.