392 HISTORY OF ASTRONOMY. 



Clark has discovered with, telescopes of his own manu- 

 facture : 



Right Ascension. South Declination. 



61, 42m. 10s. 140 B8 , 47 ,, M ag. 6. j Discovered ^ ^ 4| 



8 Sextantis, 9k 45m. 4s. 7 24' 1" 4. L h object lass> 



12h. Om. 20s. 19 31' 45" " 7. ) 



95 Ceti, 3h. 10m. 42s. 1 28' 48" " 6*. ) Discovered with the H 



6h. 4m. 19s. 4 38' 11" " 6. Hnch, sold to Mr. Dawes. 



18h. 17m. 11s. 1 39' 23" " 6|. > Discovered with the Am- 



19h. 50m. 353. 2 38' 1" " 6. \ herst College telescope. 



Mr. Clark is now engaged on a model instrument de- 

 signed to answer some of the purposes of a regular heli- 

 ometer. Its micrometer will embrace two degrees, and 

 each spider line be supplied with an eye-piece of high 

 power. Its efficiency will of course depend much on the 

 accurate running of the driving clock, while the observer 

 is passing his eye from one object to the other. By re- 

 moving one of the eye-pieces, it becomes an ordinary 

 micrometer for all small distances. 



TELESCOPES BY CHARLES A. SPENCER, OF CANASTOTA 

 NEW YORK. 



Mr. Spencer has long been celebrated for the ex- 

 cellence of his microscopes. In 1851, a committee of 

 the American Association for the Advancement of 

 Science, consisting of Professor J. W. Bailey, Dr. J. 

 Torrey, Professor J. Lawrence Smith, Dr. W. J. Burnett, 

 and Dr. Clark, made a report on Spencer's microscopes, 

 awarding the highest prize to his lenses, and concluded 

 with the remark, "the committee believe it would be an 



