I 



44 TRANSACTIONS OF THE [DEC. 21, 



This exaniinatioD seems to show it Avill 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. 



Yice-President Dr. Hubbard in the chair. 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 Interrupter, both by Dr. M. I. Pupin. 



No Abstract. 



December 21st, 1891. 



Stated Meeting. 



Vice-President Dr. Hubbard in the chair. One hundred and 

 fifty persons present. 



The minutes of December 14th were read and approved. 



Prof. D. S. 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 

 Academv were invited to attend. 



