318 TRANSACTIONS OF THE [mAY 3, 



were read and approved. The Secretary presented the follow- 

 ing nominations for resident membership from the Council and 

 they were thereupon elected. 



A. A. Anderson, Gary N. Calkins, W. H. Daily, W. B. Dev- 

 ereux, Robert E. Flemraing, Frederic Gallatin, Max Heller, 

 Alexander Maitland, T. Commerford Martin, Geo. N. Miller, 

 Frank Russak, Wm. I. Sommerfield, C. E. Trippler, Alfred A. 

 Whitman, Charles T. Wills. 



Mr. Herbert Bolton, Assistant Keeper of the Museum of 

 Owens College, Manchester, England, was elected Correspond- 

 ing Member. On motion the back dues of Mr. Arthur Willey 

 were remitted because of distinguished services to science, and 

 he was changed from active to corresponding membership. 



The Section of Astronomy and Physics then organized and 

 was called to order by the Chairman, Mr. P. H. Dudley. Twenty- 

 five members and guests being present. At the request of the 

 Chairman, the minutes of the previous meeting were read and ap- 

 proved. 



Wm. Hallock then presented a paper on " An Hydraulic 

 Working Model of the Wheatstone Bridge," which showed by 

 means of a simple manometer, the function of a galvanometer or 

 electrometer in the electrical circuit. The effect of self-indue, 

 tion, and that of capacity was also clearly shown. 



J. K. Rees then showed enlarged prints made from negatives 

 of the moon obtained at Lick Observator}^, and added brief re- 

 marks about them. He also showed the drawings made at the 

 Jjowell Observatory, City of Mexico, of certain markings on 

 Mars, Venus and Mercur}'. 



These markings and their probable causes were discussed by 

 William Hallock, J. K. Rees and C. A. Post. 



J. K. Rees, Harold Jacoby, and H. S. Davis then presented a 

 paper on the " Variation of the Latitude and Determination of 

 the Constant of Aberration." They gave the value of 20.457" 

 to this constant, with a probable error of .013. The value as- 

 signed by the Paris Conference of IS'JG was 20.47/' 



