1890.] NATURAL SCIENCES OF PHILADELPHIA. 471 



Mr. Isaac C. Martindale was elected Treasurer September 23rd 

 to supply the vacancy caused by the death of Mr. Wm. C. Henszey 

 which occurred September 7th. Mr. Chas. P. Perot was elected 

 September 30th to fill the vacancy in the Finance Committee caused 

 by the election of Mr. Martindale to the Treasurership. 



The first award of the Hayden Memorial Medal was made, (m the 

 recommendation of the Committee appointed to report on the sub- 

 ject, to Prof. James Hall as a well merited recognition of the value 

 of his geological work. 



A second invitation having been received from the University of 

 Pennsylvania to remove to a position on the University grounds in 

 West Philadelphia, the subject was maturely considered by the 

 Council of the Academy and on its recommendation again declined 

 by the society at a meeting held March 11th. 



Apart from the purely scientific operations of the society, the most 

 important event of the year was the beginning of work on the pro- 

 posed new building. For the details and dates of the work of 

 construction as far as it has advanced reference is made to the 

 report of the Curators. 



All of which is respectfully submitted. 



Edw. J. Nolan, 



Recording Secretary. 



REPORT OF CORRESPONDING SECRETARY. 



While the correspondence of the past year has been of the usual 

 routine character it continues to show the steady progress of the 

 Academy in its exchange relations with the scientific societies of the 

 world. Each year adds many exchanges, rendering the library 

 more useful to those w^ho consult it with the view of obtaining a 

 knowledge of what is being published abroad. The study of the 

 natural sciences seems to be increasing, so that in nearly every town, 

 of any size, in the civilized world, societies are established and soon 

 thereafter a publication of their work in serial form begins. 



During the year sixty-eight circular letters and sixty-five cards 

 of acknowledgements of the reception of our publications have been 

 received from societies and other bodies. The nearly equal numbers 

 of the two methods of acknowledgement is doubtless due to the fact 

 that the larger portion of our exchange is sent by mail and is 

 promptly acknowledged by card. ,_^ . 



