44 TRANSACTIONS OF THE [prc. 21, 
This examination seems to show it will be desirable to make posi- 
tives from all of Rutherfurd’s negatives of the moon when her age 
was less than thirty-six hours greater than the first quarter. 
Such an examination will be begun very shortly. 
Meeting adjourned. 
December 14th, 1891. 
STaTED MEETING. 
Vice-President Dr. Hupparpin thechair. About fifteen persons 
present. 
The minutes of November 30th were read and approved. 
The following paper was read, entitled :— 
The Railway Problem in China. 
BY JOHN A. CHURCH. 
(No abstract.) 
At the close of this paper, the Academy adjourned to the Chemical 
Lecture-Room, where the following papers were read, entitled :— 
A new form of Vacuum Tube, and A new Electrodynamic Cur- 
rent Interruptor, both by Dr. M. I. Pup. 
No Abstract. 
December 21st, 1891. 
STATED MEETING. 
Vice-President Dr. Hupsparp in the chair. One hundred and 
fifty persons present. 
The minutes of December 14th were read and approved. 
Pror. D. 8. Martin announced that during the coming week an 
exhibition of geographical apparatus, maps, charts, globes, etc., 
would be opened at the Arsenal Building in Central Park. The 
exhibition would remain open for two weeks, and members of the 
Academy were invited to attend. 
