Auzout, Adrian

was a French astronomer, and a picmber of the old academy of France, into which he was | received in 1666. He is principally known for having brought to perfection the micrometer, an instrument usually fitted to a telescope, in the focus of the objectglass, for measuring small angles or distances. This he published in 1666, but Mr. Townley, in the Philosophical Transactions, claims it for one of our countrymen, Mr. Gascoigne. He relates that from some scattered letters and papers of this gentlemen, who was killed in the grand rebellion, he had learned that before its breaking out, he had invented a micrometer, of as much effect as that made by M. Auzout, and had made use of it for some years not only in taking the diameters of the planets, and distances upon land, but in determining other matters of nice importance in the heavens, as the moon’s distance, &c. Mr. Gascoigne’s instrument also fell into the hands of Mr. Townley, who says farther, that by the help of it he could make above 40,000 divisions in a foot. The French writers endeavour to deny all this, and conclude with an assertion, as illiberal as it is false, that every nation has a zeal for its literary glory, but that in England alone this zeal is pushed to ardour and to injustice. Auzout, however, was an astronomer of acknowledged abilities. He died in 1691. 1


Hutton’s Mathematical Dict. in art. Micrometer. Eloges des Academiciens, vol. I. p. 178, edit. 1799. —Dict. Hist.