1894. | NEW YORK ACADEMY OF SCIENCES. 7 
STATED MEETING. 
October 8th, 1894. 
The Section of Astronomy and Physics organized immediately 
with President Rees in the chair, and thirteen members and 
guests present. 
At the suggestion of President Rees, Prof. Mayer of Stevens 
Institute made a few remarks upon his summer experiences, 
especially in England at the meeting of the British Association 
for the Advancement of Science. He spoke quite fully of the 
discovery by Lord Rayleigh of a new substance in the air; its 
“preparation by two methods, and its properties. 
Remarks upon the subject were made by President Rees and 
Capt. Casey. 
The first paper of the evening was by President Rees, ‘“ Re- 
marks on the Observations for Variations of Latitude made at 
Columbia College and at the Royal Observatory at Naples.” 
President Rees detailed the preliminaries and negotiations 
which led to the inception of this work, and the general plans of 
the observations, as well as the details of manipulating the in- 
struments; giving also the method and principle of the calcula- 
tions and corrections. 
In all about 2400 pairs of stars were observed at each Observ- 
atory, during the 14 months covered by the original plan. 
The observations are, by mutual agreement, to be continued 
four nights in each two weeks, during the next two or three years. 
The calculations are not yet completed, but point to an ex- 
treme variation of about 0’’.35 as a first approximation, with a 
probable error of one evening’s work of 0’’.07. 
The paper was discussed by Capt. Casey, Prof. Mayer and 
others. 
The second paper was also by President Rees on, ‘‘ The Meas- 
uring Apparatus for Astronomical Photographs, made by Rep- 
sold & Sons of Hamburg, and presented to the Columbia Col- 
