1880.] 157 



in America, and by a member of this Society, and published 

 in its Proceedings. He remarked on (1) the extreme sensi- 

 tiveness of the plate, and (2) on the extraordinary perfection 

 of the running machinery of the driving clock, which was 

 required to hold the image steadily upon the plate for fifty 

 minutes, ten minutes being hitherto considered the maxi- 

 mum. 



The letter is as follows: — 



271 Madison Avenue, New York, 

 October 9tli, 1880. 

 My Dear Barker : — 



I have succeeded in photographing the nebula in Orion. It took an ex- 

 posure of fifty minutes which, as you can well imagine, was a hard test 

 for the driving clock. This is the first time a nebula has been photo- 

 graphed. I used the ne v Clark triple objective of 11 inches aperture, 

 mounted on the equatorial stand I made some years ago. Tliis objective 

 is especially corrected for the photographic rays. 



The pictures show the mottled appearance of the bright portion of the 

 nebula admirably. It will take some time to discuss the pictures taken 

 since Sept. 30th, as comparisons must be made with the drawings of Lord 

 Rosse, Bond and others. 



The importance of the result turns on the fact that photographs will 

 show with certainty any changes in the nebula and perhaps enable us to 

 determine some of the laws ruling these elementary forms of matter. They 

 may indicate the process of the genesis of solar systems. 



If it suits your convenience will you call the attention of the Philosophi- 

 cal Society to this matter, and oblige 



Yours truly, 



Henry Draper. 



Pending nominations Nos. 904, 909 to 920 were read. 



Mr. Price reported in behalf of the Committee that a dis- 

 course on the life and character of the late President of the 

 Society, George B. Wood, M.D., LL.D., was delivered by 

 Dr. Henry Hartshorne, in the hall of the College of Sur- 

 geons, on the 11th instant, and asked that 1000 extra copies 

 be printed for circulation, which was so ordered ; and the 

 thanks of the Society presented to the College for the free 

 use of its room. 



On motion it was resolved that the Curators be authorized 

 to permit a copy to be made of Martin's portrait of Franklin. 



The ballot boxes being examined by the presiding officer, 



