4 o8 THE POPULAR SCIENCE MONTHLY. 



lished in the annals of the New York Academy of Sciences, one 

 hundred and seventy-five plates of the sun, one hundred and 

 seventy-four of the solar spectrum, four hundred and thirty -five 

 of the moon, and six hundred and sixty-four of star clusters. The 

 reduction of the measures of the Pleiades plates, taken with the 

 thirteen-inch instrument and measured with the improved ma- 

 chine, undertaken according to the understanding between Mr. 

 Rutherfurd and the college authorities by Prof. Rees and Mr. 

 Harold Jacoby of the observatory, and completed and published 

 only a few days before Mr. Rutherfurd's death, but too late to be 

 examined by him, seem, says Prof. Rees, to indicate an accuracy 

 of measures comparable with the best recent heliometer work. 

 Yet they were all taken between 1865 and 1874. It is intended to 

 continue the reductions till all the measures made with the im- 

 proved machine — filling some twenty folio volumes of about two 

 hundred pages each — are finished ; then to measure the negatives 

 that remain unmeasured, and proceed to their reduction. 



Prof. Gould emphasizes the fact that all these plates were 

 made some years before the discovery of the dry-plate process, by 

 the aid of which celestial photography has made such wonderful 

 progress in recent years ; and " we owe to him not merely the 

 first permanent records of the relative positions, at a given mo- 

 ment, of all the celestial objects impressed upon the sensitive 

 plates, but the means and the accomplishment of the actual con- 

 version of these records into actual numerical data." 



Mr. Rutherfurd demonstrated, contrary to the prevailing opin- 

 ion, that the albuminated collodion film could be made stable on 

 glass under all conditions of atmospheric change. 



Mr. Rutherfurd was a member of the International Meridian 

 Conference that met in Washington in October, 1885, and took a 

 prominent part in its work, framing and presenting the resolution 

 that embodied the conclusions of the conference. He was invited 

 by the French Academy of Sciences in 1887 to become a member 

 of the International Conference on Astronomical Photography 

 held in Paris in that year, and was given by the President of our 

 National Academy of Sciences the appointment as its representa- 

 tive, but the condition of his health forbade his serving. He was 

 an Associate of the Royal Astronomical Society. He was an 

 original member of the National Academy of Sciences, which was 

 incorporated by act of Congress in 1863. In 1867 he was elected 

 President of the American Photographical Society, in the official 

 board of which he had served for many years as first vice-presi- 

 dent. During his administration the society became the Photo- 

 graphical Section of the American Institute. For many years 

 he was not only a trustee of Columbia College, but one of the 

 most active and hard-working members of that body. Mr. Ruth- 



