Page:The Biographical Dictionary of America, vol. 02.djvu/235

 CLARK

CLARK

became interested in grinding and polishing re- flectors for telescopen, and Mr. Clark took up the work and aided his son in experimenting with reflectors, which by liis advice they abandoned at considerable sacrifice and commenced the manufacture of refracting telescopes. Mr. Clark discovered in 1853 two new double stars with a 45 -inch glass of his own manufacture. In 1853, with a glass of 7^ inch aperture, he discovered 95 Ceti and reported his discoveries to the Rev. W. R. Dawes, the famous double-star observer of England, who thereupon purchased from him this glass and afterward four others, including the 8-inch glass, which in the hands of Huggins be- came well known. In 1859 he was the guest of Dawes in England where he visited the Green- wich observatory, attended a meeting of the Royal astronomical society, and met Sir John Herschel -and Lord Rosse. He sold one equatorial mount- ing and two object glasses, one 8, and the other 8| inches, and the results from the use of these glasses were published by Mr. Dawes in the monthly reports of the Royal astronomical so- ciety, giving to the American manufacturer wide reputation. In 1860 Alvan Clark & Sons es- tablished themselves at Cambridgeport, Mass., and Dr. F. A. P. Barnard ordered for the Univer- sity of Mississippi a telescope to be larger than any refractor ever before put in use. The civil war preventing the delivery of the instrument, it was sold in Chicago and was afterward in charge of S. W. Burnham. Among the larger glasses made by the firm is a 124-inch aperture for the Pritchett school institute, Glasgow, Mo., and one of the same size for Dr. Henry Draper of New York city; one of Hi inches for the Austrian observa- tory, Vienna; one of 11 inches for the observa- tory at Lisbon, Portugal; a 12-inch glass for the Wesleyan universitj-, Middletown, Conn., and a 15i-inch glass for the University of Wisconsin. In 1871-72 they built the 26-inch clear aperture telescope for the United States government, for which they received §46,000; and con.structed one of equal size for Leander J. McCormick of Chi- cago, which was presented to the UniA-ersity of Virginia. He received the degree of A.M. from Amherst, 1854, Princeton, 1865, Chicago, 1866, and Harvard, 1874, and was a fellow of the American academy of arts and sciences. The Proceedings of the Royal astronomical society gives a list of liis discoveries made with his own telescopes. He died in Cambridge, Ma.ss., Aug. 19, 1887.

CLARK, Alvan Graham, lens maker, was born in Fall River, Mass., July 10, 1832; son of Alvan and Maria (Pease) Clark, and descended from Barnabas Clark, one of the earliest settlers of Plymouth colony. He was educated at the jjub- lic schools of Cambridgeport, learned the trade of a machinist and worked with his brother, George

Bassett, in making lenses, becoming a member of the firm of Alvan Clark & Sons in 1852. He was a successful observer of astronomical phe- nomena and discovered fourteen intricate double stars, among them the companion to Sirius, re- ceiving in 1862 the Lalande gold medal of the French imperial academy of sciences. He visited Europe several times and was sent by the United States gov- ernment to observe the eclipse of the sun with Winlock at Shel- by ville, Ky., in 1869, and the transit of Venus at Jarez, Spain, in 1870, and with Harkness, the solar eclipse in Wy- oming Territory in 1878. In 1882 he com- pleted a 30-incli ob- ject glass for the government of Russia. He was made a fellow of the American academy of arts and sciences, of the American association for the advancement of science, and a member of the Cambridge and Union clubs. He received a gold medal from the Russian government for excellence of telescopic objectives. Among his larger tel- escopes are the Yerkes refractor, 41i-inch aperture; Lick observatory, California, 36-inch;

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Pulkova observatory, Russia, 30-inch; Wash- ington naval observatory, 26-inch; McCor- mick, University of Virginia, 26-inch; and those of lesser power at Princeton, Denver, Rochester, Evanston, Madi.son, and Vienna, ranging from 12 to 24 inches. In May, 1897, he delivered to the Yerkes observatory. Lake Geneva, Wis., the lenses for the most powerful telescope in Amer- ica, which cost the labor of three years with two assistants, conveying them from Cambridgeport to Chicago in a special drawing-room car. He