1891.] NEW YORK ACADEMY OF SCIENCES. 41 



Mr. Frank M. Chapman was nominated as a Resident Member 

 by Professor J. A. Allen. 



The Astronomical Section then organized, Professor J. K. Rees 

 in the chair. Mr. Jacoby, the Secretary, read the following papers 

 ))y title : 



I. Transit Factors for the Observatory of Columbia College. 



BY J. T. MONELL AND C. R. MANN. 



II. The Rutherfurd Photographic Measures of the Group of the 



Pleiades. 



BY' HAROLD JACOBY. 



The following papers were then read, entitled: 

 Report upon the Meeting of the National Academy of Sciences. 



BY HAROLD JACOBY. 



(Abstract.) 



At the meeting of the National Academy of Sciences held at 

 Columbia College, November 10th to 12th, the following papers of 

 a mathematical nature were read : Certain New Methods and Re- 

 sults in Optics, by Professor Charles S. Hastings; New Pendulum 

 Apparatus, by Professor T. C. Mendenhall ; Astronomical Methods 

 of Determining the Curvature of Space, by Professor C. S. Peirce ; 

 Variation of Latitude, by Professor S. C. Chandler ; Color System, 

 by Professor 0. N. Rood ; Reduction of Rutherfurd's Photographs, 

 by Professor J. K. Rees; Measurement of Jupiter's Satellites by 

 Interference, by Professor A. A. Michelson. 



Professor Hastings's paper contained some new and very simple 

 demonstrations of optical formulae already known, as well as certain 

 important formulae altogether new, including a general expression 

 for magnifying power applicable to both telescopes and microscopes. 

 Professor Peirce presented astronomical evidence tendiug to show 

 that space posses.«es a negative curvature, and called attention to 

 various methods of conducting an investigation of this property of 

 space. Professor Chandler exhibited curves shoAving that the re- 

 cently discovered variation of latitude could be made to explain 

 certain hitherto unaccountable discordances in older observations. 

 His paper was followed by considerable discussion among the as- 

 tronomers present. Professors Young, E. C. Pickering, C. S. Peirce, 

 Abbe, and Dr. Gould taking part. The chief question debated was 

 whether the variation has a terrestrial or celestial origiu. The 

 investigations are being published in the Astronomical Journal. 

 Vol. XL— 4 



