1887.] NEW YORK ACADEMY OF SCIENCES. 77 



been made by Prof. James B. Mackintosh, of Lehigh Univer- 

 sity. 



Jannary 24, 1887. 



Stated Meeting. 



The President, De. J. S. Newberry, in the chair. 



A very large audience present in the East Lecture Koom of 

 the Library Building, Columbia College. 



The first lecture of the Popular Lecture Course was given by 

 Prof. William Libbey, of Princeton College, on 



RECENT explorations IN ALASKA. 



(Illustrated with lantern views.) 



January 31, 1887. 



Stated Meeting. 



The First Vice-President, Prof. 0. P. Hubbard, inthechair. 



Thirty- four persons present. 



Mr. B. B. Chamberlin exhibited two specimens of tour- 

 maline from Washington Heights, one of them being black, in 

 oligoclase, the other a spreading or radiating crystal. 



The following paper was read by title: 



A REVIEW of the CH^TODONTID^ OF NORTH AMERICA, 



by Carl H. Eigenmann and Jennie E. Hornung. 

 (Published in the Annals, Vol. IV.) 

 Prof. W. P. Trowbridge read a paper 



on sub-surface water-supply for cities and TOWNS. 



Two or three years ago, I prepared a paper for the Sanitary 

 Engineer, describing the driven wells, and the method of con- 

 necting them with pumps, by which a large supply of pure 

 water had been obtained for the city of Brooklyn from the 

 gravel deposits on Long Island. The simplicity of the means 



