286 CARNEGIE INSTITUTION OF WASHINGTON. 



ment of apparatus and technique may not be disturbed by the requi- 

 sition of the apparatus for other experimental work. 



The wood and zinc floors in the rooms for research with animals have 

 been replaced with new floors of cement and terrazza. This is a sub- 

 stantial and much-needed improvement. 



Owing to the concrete construction of the building, much difficulty 

 has been experienced in the past (particularly in the winter, when the 

 snow has accumulated on the roof) by the condensation of moisture 

 on the ceilings of rooms on the third floor of the laboratory. This 

 water, dropping upon the apparatus in these rooms, has caused frequent 

 annoyance. The ceilings have therefore been painted with a specially 

 prepared cork paint, such as is used on battleships and submarines to 

 prevent undue condensation of moisture. 



A new inter-communicating telephone system, more especially 

 adapted to the needs of the Laboratory, has been successfully installed. 



ADDITIONS TO EQUIPMENT. 



Reconstruction of the bed calorimeter. — Heretofore the active experi- 

 menting on technique, which required the continual use of the bed 

 calorimeter and changes in its construction, has made it impossible to 

 give this apparatus a permanent form. Inasmuch as there was no 

 immediate prospect of a fundamental change in the principle or tech- 

 nique of the apparatus, it was completely reconstructed during the 

 summer of 1914 in accordance with the latest and most approved design, 

 the mass of metal between the copper and zinc walls being removed, 

 and the whole apparatus made substantial and permanent. In this 

 construction we profited much by the experience of Professor Lusk and 

 his co-workers at Bellevue Hospital. The apparatus will be given the 

 usual electrical and alcohol check-tests and thereafter used continuously 

 for experiments with normal and pathological subjects. 



Respiration apparatus for muscular work. — In connection with an 

 extensive study of the metabolism incidental to walking, a special 

 modification of the unit form of respiration apparatus in use in this 

 Laboratory was adjusted to the treadmill designed by Mr. Metcalf, 

 formerly of our staff. The respiration apparatus is a somewhat modi- 

 fied form of the apparatus employed by Dr. Cathcart in his experiments 

 on the muscular work of bicycle riding. The apparatus functionates 

 perfectly and an extensive research was carried out with it in 1914 by 

 Dr. Murschhauser. Supplementary apparatus for recording the height 

 to which the body was moved, the number of steps taken, the distance 

 walked, and similar measurements, was likewise designed and con- 

 structed for this research. 



Dog treadmill. — A dog treadmill, of the admirable form devised by 

 Professor Franz Tangl of Budapest, was secured from Professor Tangl's 



