TWENTY-SECOND ANNUAL REPORT 



117 



ATTENDANCE AT TIIK AQUARIUM BY MONTHS, 1917. 



2,546 

 2,773 

 3,186 

 4,744 

 5,106 

 6,231 

 6,330 

 7,103 

 5,912 

 3,885 

 2,952 

 1,590 



Total 



.1,595,118 



4,370 



Density Record. — The daily observations on the condition 

 of the water of the Harbor, commenced at the Aquarium in 1903, 

 have been continued practically without interruption. These 

 unique records, published annually in our report, have been use- 

 ful not only to the Aquarium, but of important public service 

 on many occasions. 



Record of monthly mean temperatures and specific gravi- 

 ties at the New York Aquarium during the year 1917 (from 

 daily observations made by Mr. W. I. DeNyse)."' 



Harbor Water — Temperature and Density. 



Temperature. Specific Gravity. 



January 42° 



February 39° 



March 39° 



April 43° 



May 48° 



June 57° 



July 63° 



August 69° 



September 68° 



October 61° 



November 53° 



December 44° 



1.014 

 1.015 

 1.013 

 1.009 

 1.011 

 1.011 

 1.012 

 1.013 

 1.015 

 1.015 

 1.013 

 1.014 



*Density obscm ations were made with samples of water brought to a tem- 

 perature of 60° Fahr. 



