could keep a star under a micrometer wire for long periods of time. 

 This telescope was equipped with a double eyepiece micrometer and 

 "an ingenious apparatus for sketching the solar spots somewhat on the 

 principle of a Camera Lucida." (See fig. 21, p. 91.) 



In 1857 Dawes sold his 6y3-inch objective and tube, which had been 

 made by Merz of Munich, and bought from the Clarks a new telescope 

 to fit the German equatorial mount. With this 7-inch instrument Dawes 

 and Lassell one evening were able to see Enceladus, and Lassell ex- 

 pressed surprise that this Saturnian satellite was so readily apparent in 

 such a small telescope. When Alvan Clark arrived in England with the 

 new instruments in 1859, Dawes sold the old telescope to George Knott 

 (q.v.). 65 



The 18/2-inch Dearborn equatorial, the Clarks' first world's largest, 

 had a stormy history. It was ordered by the University of Mississippi 

 (q.v.) which, under the presidency of F. A. P. Barnard, was strengthen- 

 ing its science facilities. An astronomical observatory — an exact replica 

 of Pulkowa — was built in Oxford, Mississippi, in 1859. 66 With full con- 

 fidence in the Clarks' ability, Barnard asked them to make a telescope 

 of 1 9 inches aperture. He even offered to comply with the usual terms : 

 1/3 down, J/3 when the objective was tested, and 1/3 when the instrument 

 was delivered. The Clarks, more hesitant, offered to try a 15-inch lens, 

 which they would donate to Mississippi if it were inferior to the Harvard 

 glass. They compromised — the Clarks tackled an i8J/ 2 -inch objective 

 but would take no money until the instrument was finished. 67 



The glass blanks, ordered from Chance Bros., arrived within a few 

 months. The Clarks, meanwhile, had moved to premises large enough to 

 accommodate this work. By the summer of 1861 the achromatic lens 

 was near enough to completion for the Clarks to ask Barnard to come 

 to Cambridgeport to see it, but the escalation of the war between the 

 states put an end to commerce between Mississippi and Massachusetts, 

 and the Clarks were stuck with a lens insured for $1000. In early Janu- 

 ary 1863 representatives of the newly formed, and wealthy, Chicago 



65 See letters from William R. Dawes to George Knott (published in Observatory, 

 vol. 33 [1910], pp. 343~359> 3 8 3~398, 4I9-43 1 * 473-47 8 )- 



66 Mable Sterns, Directory of Astronomical Observatories in the United States, op cit., 

 p. 116. 



67 John Fulton, Memoirs of Frederick A. P. Barnard (New York, 1896), pp. 244-246. 



54 



