266 CARNEGIE INSTITUTION OF WASHINGTON. 



Pursuit-meter apparatus. — Considerable time has been spent during 

 the year in perfecting and rebuilding the pursuit-meter apparatus 

 which was referred to in the last annual report under the title of 

 ''recorder for adequacy of motor adjustments." 



Respiration chamber for large animals. — For use in the research on 

 the undernutrition of beef animals, a large respiration chamber was 

 constructed by the Laboratory mechanician, Mr. W. E. Collins, at the 

 New Hampshire Agricultural Experiment Station in Durham. This 

 animal respiration chamber is, in principle and general form, like the 

 group respiration chamber referred to in an earlier report, but is smaller 

 and is modified to meet the requirements of a research with such large 

 animals as full-grown steers or horses. The inside chamber is 9 feet 

 7.5 inches long, 5 feet 5 inches wide, and 7 feet high, with the entrance 

 at the back. The animal stands on a platform slightly inclined. This 

 platform is movable, with the front end supported by chains and springs 

 in such a manner that connection with a pneumograph and kymograph 

 gives a graphic record of the movements of the animal. Accessory 

 apparatus, similar to that used with the group respiration chamber, 

 provides for the measurement of the carbon dioxid given off by the 

 animals by the determination of the carbon dioxid in an aliquot sam- 

 ple of the ventilating air current. 



COOPERATING AND VISITING INVESTIGATORS. 



Dr. Elliott P. Joslin, who served as lieutenant-colonel in the Medical 

 Corps in France during the war, has returned to this country and is 

 now preparing for publication the results of his studies on metabolism 

 in diabetes mellitus. 



Dr. Fritz B. Talbot continued his cooperation in the studies of 

 normal children up to the time of their completion on July 1, 1919, and 

 is assisting in the preparation of the results for publication. 



Dr. J. Arthur Harris attended to the major part of the details of 

 proof-reading and oversight of the report on the biometric analysis of 

 the results of metabolism studies in the Nutrition Laboratory, and has 

 prepared several brief summaries of this analytical study. 



Mrs. Cornelia Golay Benedict has continued her investigations into 

 the calorific values of extra foods and has prepared a second report 

 of her findings in this field of practical interest. 



A large share of the success of the research with steers carried out at 

 the New Hampshire Agricultural Experiment Station is due to the 

 cooperation of Director J. C. Kendall and Professor E. G. Ritzman, 

 whose scientific interest and attention to the details of the research 

 have been unfailing. 



An especially helpful feature of the research at the New Hampshire 

 Agricultural Experiment Station has been the privilege of conference 

 with Professor H. P. Armsby, of State College, Pennsylvania, who 



