PHILOSOPHICAL SOCIETY OP WASHINGTON. 43 



the cremaster proper, in which the membrane may be caught; 

 the ridges being, in this species, very narrow, smooth, and 

 shallow, and the ordinary ventral knobs obsolete. 



Mr. Newcomb's communication was entitled 



A THERMODYNAMIC THEORY OP THE SPECTRUM. 



The subject matter and its discussion were reserved by Mr. 

 Newcomb for publication. 



165th Meeting. June 21, 1879. 



The President in the Chair. 

 Thirty-five members present. 

 The minutes of the last meeting were read and adopted. 



The first paper was by Mr. J. R, Eastman, entitled 



SOME RESULTS FROM THE DISCUSSION OF THE OBSERVATIONS OP 

 THE TRANSIT OF MERCURY OP MAY 6, 1878. 



(abstract.) 



In response to a circular issued from the Naval Observatory, 

 more than one hundred observations were made and forwarded 

 to the Observatory, where they have been reduced and discussed, 

 and will soon be printed. 



Fifty-two observations were made of the first contact, eighty- 

 three of second, eighty-two of third, and eighty of fourth. 



In obtaining the final results each observation was assigned 

 its appropriate weight according to the scale in which three re- 

 presented the best observation. 



Three observations of first, ten of second, ten of third, and 

 seven of the fourth contact were given the weight three. 



The results from the different weights for geometric observa- 

 tion are 



Assuming that the results from the observations with weight 

 3 best represent the true phenomena, the difference between the 

 computed places from the data in the American and English 

 ephemerides and the observed places are C. — 0. 



