PHILOSOPHICAL SOCIETY OP WASHINGTON. 199 



Remarks were made by Messrs. Baker, Taylor, and Hark- 



■ NESS. 



Mr. Newcomb made preliminary remarks on 



THE RECENT TRANSIT OF MERCURY, 



describing the optical and physical phenomena as noticed by him- 

 self and others. He observed the transit with a three-inch tele- 

 scope, and saw a decided black drop ; also a small white spot on 

 the disk of Mercury. He stated that this transit afforded con- 

 firmation of Le Terrier's conclusion respecting the increased 

 motion of Mercury's perihelion. 



Mr. Harkness made remarks on the physical phenomena, 

 stating that he had never seen the black drop, though others 

 have noticed it. 



Mr. Hall spoke of the results of observations at the Washing- 

 ton Observatory, and added that observations had been made at 

 nearly sixty stations ; but the first contact was generally lost. 

 Photographs were taken at Cambridge, Washington, Ann Arbor, 

 and by a party of French astronomers at Ogden. 



145th Meeting. June 8, 1878. 



Yice-President Taylor in the Chair. 

 Twenty members and visitors present. 

 Mr. J. W. Powell made a communication on 



THE evolution OF LANGUAGE. 



The subject was discussed by Messrs. Welling, Taylor, 

 Ward, Farquhar, and Gill. 



Mr. E. B. Elliott presented the following communication on 

 musical intervals. 



