THE DIRECTOR'S REPORT. 21 



made by the head of each course of instruction on a given date, 

 May 15 of each year, on the basis of a detailed application and 

 letters of recommendation. 



The number of investigators was 194, the largest registration 

 in the history of the Laboratory. It is interesting to note that 70 

 of these were "under instruction," that is for the most part 

 graduate students from University laboratories. The oppor- 

 tunity that is afforded these students of comparing the teachings 

 and methods of the various University laboratories is a great 

 benefit educationally for them. The large attendance of workers 

 of this age augurs well for the future of the Laboratory which 

 must depend for its growth on the development and maintenance 

 of the devotion to its interests of successive generations of scien- 

 tific workers. 



2. Library. The report of the Acting Librarian is given in 

 another place. It details the plans and the means available for 

 enlargement of the library, which we should now set down as one 

 of the principal ends to be emphasized in the development of the 

 Laboratory during the next few years. Next to providing the 

 materials for investigation, and facilities of modern and adequate 

 type for the work of research itself, there is no material service 

 that the Laboratory can render of greater importance than a 

 thoroughly good working library. To that end a wing of the new 

 building is devoted with stack space for 100,000 volumes. If this 

 capacity be compared with the present possessions of the library, 

 13,000 bound volumes and about 10,000 reprints and pamphlets, 

 it will be realized that our efforts on behalf of the library need not 

 relax for lack of space for some years to come. The Acting 

 Librarian is to be congratulated on getting an active policy of 

 expansion into operation before the new quarters are entirely 

 ready. 



3. The Report of the Treasurer (pp. 5-12). Particular interest 

 attaches to the report of the Treasurer this year because it 

 includes the new endowment funds and the results of building 

 operations as well as the customary current accounts. The 

 assets of the Laboratory are thus of quite a different order of 

 magnitude at the end of 1924 as compared with previous years: 

 $1,887, 774. 14 on December 31, 1924 as compared with $445,504.69 

 on December 31, 1923. Of this amount $909,541.86 represent 



