416 PROCEEDINGS OP THE AMERICAN ACADEMY 



An invitation to attend the semi-centennial meeting of the 

 Oberhessische Gesellschaft fiir Natur- und Heilkunde at 

 Giessen was also read. On the motion of the Corresponding 

 Secretary, it was 



Voted, To accept these invitations. 



'Dr. Otto W. Struve, of Pulkowa, read a paper on Aber- 

 ration. 



Professor Lovering showed the bearing of the refined obser- 

 vations of the Pulkowa Observatory upon the question of the 

 influence of the movement of the ether upon aberration and 

 refraction. 



The following papers were presented : — 



Results of the Comparisons of Three Independent Copies 

 of the Imperial Yard and of Four Independent Copies of the 

 Metre of the Archives. By William A. Rogers. 



On the Earliest Observation of a Variable Star. By Seth 

 C. Chandler, Jr. 



On the Photographs of Stellar Spectra made by the late 

 Dr. Henry Draper. B}^ Edward C. Pickering. 



The following papers were presented by title : — 



On Substituted Pyromucic Acids. By Henry B. HilL 



On certain Parabrombenzyl Compounds. By C. Loring 

 Jackson and G. T. Hartshorn. 



Notes on the Crjqotogamic Flora of the White Mountains. 

 By William G. Farlow. 



Seven hundred and sixty-second Meeting. 



May 9, 1883. — Monthly Meeting. 



The President in the chair. 



Tlie Corresponding Secretary read letters from the Congres 

 International des Americanistes, at Copenhagen ; from Seiior 

 Anguiano, Director of the National Observatory of Mexico, 

 at Tacubaya ; from Messrs. Huxley and Schmidt, acknowl- 

 edging election as Foreign Honorary Members. 



On the motion of the Corresponding Secretary, it was 



