MUSEUM OF COMPARATIVE ZOOLOGY. 21 



desirable it is to secure a number of such experts each year to 

 handle the specialized and exceedingly diverse branches of this 

 important course. 



During the year, the expenditures of the Secondary Enrich- 

 ment Investigation amounted to about $16,000. The field work 

 originally contemplated was practically completed and the labo- 

 ratory studies, both in the Department laboratories in Cambridge 

 and at the Geophysical Laboratory of the Carnegie Institution 

 in Washington, were well advanced. One particular subject of 

 research carried on by the Investigation, viz., Microscopic determi- 

 nation of the opaque minerals, was completed after four years of 

 study by Mr.. J. Murdoch, one of the graduate students of the 

 Department, and the results, accepted as a Doctor's thesis, are 

 now being published as a text-book. With support afforded by 

 the Shaler Memorial Fund, the investigation was able to study the 

 bearing of physiography on ore alteration through the work of 

 Professor Atwood and a graduate student of the Department at 

 mining camps in Montana and Utah in the summer of 1914. 



During the summer of 1915, Professor Graton studied the ore 

 deposits in four mining regions of Alaska and in three districts 

 in California; while in the laboratory, the academic year was 

 devoted to continuation of researches on American copper deposits 

 and on the microscopic character of sulphide ores. 



In addition to his courses on elementary physiography and 

 the physiography of the United States (Geology 1 and Geology 6, 

 both repeated in Radcliffe College), Professor Atwood took charge 

 of Geology 16 (Glacial geology) and gave two new half courses , 

 entitled Local field work in physiography (Geology 2) and 

 Natural resources and their conservation (Geology 15). 



Professor Atwood 's new summer course in the San Juan Moun- 

 tains of Colorado was highly successful. The opportunities for 

 gaining correct and large ideas are abundant in that field. Four 

 of the class were from other institutions. One of these has come 

 to Harvard as a graduate student in the Department, two others 

 have indicated that they hope to come here for their advanced 

 work, and each of the Harvard men who took the summer school 

 work will continue with additional courses in this Department dur- 

 ing the present year. Some provision for the continuation of such 

 work each summer, and the lengthening of the course from five 

 to eight weeks should be made, so that, as in the engineering 

 camp, a student may at very little additional expense complete 

 the college requirements for one full course of instruction by re- 



