ANNALS 



NEW YORK ACADEMY OF SCIENCES, 



VOLUME VI. 



I. — A Catalogue of Rutherfur&s Photographic Plates of the 

 Sun, the Moon, and the Stars. 



BY JOHN K. REES. 



Read March 9, 1891. 



On November 13th, 1890, Lewis M. Rutherfurd, LL.D., of New 

 York City, presented to the Columbia College Observatory all his 

 photographic negatives taken between the years 1858 and 1878. 

 Many of the plates had been measured, and these measures were 

 included in the gift. The measures fill some thirty quarto volumes. 

 Several years ago (1884) Mr. Rutherfurd gave to the Observatory 

 his 13-inch equatorial with its photographic corrector, with which 

 the photographs, taken since 1868, were made ; and at the same time 

 he donated to the Observatory his measuring engine supplied with 

 a glass scale. This improved measuring apparatus was used in 

 January, 1872, and subsequently. 



The star cluster negatives received an exposure of either three or 

 six minutes. Each negative bears the date, time of exposure, a 

 record of the barometer and thermometer readings, and other data 

 necessary for the reductions. 



The Observatory of Columbia College hopes to, issue soon the 

 reductions of many of the measures. 



Mr. Harold Jacoby aided in the preparation of the catalogue. 



Columbia College Obseevatory, New York, March 9, 1891. 

 Annals N. Y. Acad. Sci., VI, June, 1891. — 1 



