ian transit, the 4-inch object glass of the Troughton & Simms mural 

 circle, and the 9. 6-inch lens of the Merz und Mahler equatorial. 224 

 Twenty-five years later they provided this last named telescope with a 

 photometer for observations of variable stars. 2 " 5 When the Naval Observa- 

 tory was rebuilt, at the end of the century, the 9.6-inch was replaced by a 

 telescope with a 12-inch Clark objective and a Saegmuller equatorial 

 mount. 220 The comet seeker and 9.6-inch lens are now in the Smithsonian 

 Institution (q.v. ). 



During the Civil War the Naval Observatory, the former Depot of 

 Charts and Instruments, supplied the Navy with its navigational instru- 

 ments. Gillis, reluctant to rely on foreign manufacturers, wrote to Ameri- 

 can artisans, encouraging "the successful and permanent establishment of 

 American factories for all classes of instruments." 227 In particular, he re- 

 quested the Clarks to make spyglasses, as many and as soon as possible. 

 The Clarks sent him their first sample in June 1863; in their typical, un- 

 businesslike fashion, however, they neglected to include their names and 

 the price. During the next two years the Clarks sold the Navy at least 165 

 spyglasses at prices ranging from $25.75 to $35- 00 apiece. 228 



In the fall of 1 864 Gillis asked the Clarks to undertake binoculars for 

 viewing a large field under high magnification— as this was the only for- 

 eign instrument he was still compelled to purchase. Robert Tolles, of 

 Canastota, New York, had supplied him with some, but not enough, bin- 

 oculars that were better than those available from Europe. The Clarks' 

 first pair, sent to Washington in February 1865, were rated "very credit- 

 able" and "far better" than those attempted by Henry Fitz. 229 As the war 

 ended shortly thereafter, the Clarks probably made no more binoculars for 

 the Navy. 



224 Astronomical and Meteorological Observations Made at the United States Naval Observa- 

 tory During the Tear 1862, pp. vii-x. 



225 Sidereal Messenger, vol. 5 (1886), p. 88. 



226 A. N. Skinner. "The United States Naval Observatory," Science, vol. 9 (1899). 

 p. 12. 



227 James M. Gillis to Alvan Clark & Sons, 26 January 1865 (letter in U.S. Naval 

 Observatory Papers, National Archives, Record Group 78). 



228 See correspondence between Alvan Clark & Sons and James M. Gillis, 1863- 

 1865 (letters in U.S. Naval Observatorv Papers, National Archives, Record Group 

 78). 



229 Ibid. 



99 



