RECORDS. 649 



Annalen " for 1878. He showed how far from appHcable to 

 the actual facts most of these theoretical discussions and calcula- 

 tions are. 



In the discussion Professor Pupin called attention to the fact 

 that in the concentration of a heavenly body the work done by 

 gravitation might be an excessively small fraction of the total 

 work done by all the forces, including particularly the forces of 

 chemical affinity. But we cannot at present base any calcula- 

 tions on these as we know so little about them. 



Professor Rees said that if astronomers cannot yet solve these 

 problems, it is because they cannot get the proper knowledge 

 from the physicists on the physical parts of the question. 



In the third paper, Mr. W. C. Kretz related that Rutherfurd 

 took fourteen photographs in the years 1870, 1875, and 1876, 

 of the cluster in Coma Berenices. The positions of these stars 

 on the plates were measured with a Repsold measuring machine, 

 and the reduction was made by the method worked out by Pro- 

 fessor Jacoby. Great precautions were taken to eliminate all 

 possible errors. The positions obtained were compared with 

 those obtained by Chase with the Yale heliometer in 1892. In 

 this manner a catalogue of the positions and proper motions 01 

 24 stars was obtained, which was the object of the research. 



In the discussion, Professor Rees said that the Academy should 

 be proud of Mr. Rutherfurd. He also expressed appreciation 

 of the generosity of Miss Bruce, who has altogether given some- 

 thing over $22,000 for carrying out several important pieces of 

 work. 



On motion of Professor Rees, it was voted that the paper be 

 referred to the publication committee of the Council. 



The section then adjourned. Wm. S. Day, 



Secretary. 



SECTION OF GEOLOGY AND MINERALOGY. 



April 17, 1899. 



Section met at 8:15 P. M., Professor J. J. Stevenson presiding. 

 Annals N. Y. Acad. Sci., XII, June i , 1900-41. 



