l80 REPORTS ON INVESTIGATIONS AND PROJECTS. 



In researches with the respiration calorimeter just mentioned, it is planned 

 to use a treadmill of unique design, on which it will be possible for the sub- 

 ject to walk forward at any desired rate, or even to run. The construction 

 of this treadmill is well under way. 



An important factor in the measurement of heat by the calorimeter is the 

 physical observer's table, where all the heat-controlling appliances are in- 

 stalled and all temperature measurements recorded. The original table, 

 which was more or less experimentally constructed, has been replaced by a 

 substantial permanently constructed and wired table, which has been tested 

 for a year. 



The building of a third calorimeter made necessary the construction of a 

 second observer's table for controlling the calorimetric features of the ap- 

 paratus. From this table it is possible to control not only the new calo- 

 rimeter, but also one of the calorimeters controlled from the other observer's 

 table, i. e., the bed calorimeter. It is thus practicable to make experiments 

 with any two of the three completed calorimeters at one time. The special 

 features of these two tables will be described in a future publication. 



RECONSTRUCTION OF CHAIR CALORIMETER. 



In using the chair calorimeter, which is described in Publication No. 123,. 

 experience showed that the entrance as originally placed was very incon- 

 venient. As the opening was at the top, it was necessary for the subject to 

 ascend a ladder, then climb over the side of the opening, and descend a small 

 ladder to the floor of the chamber and seat himself in the chair. The method 

 of entering the apparatus was thus very complicated, and there was danger 

 that inexperienced subjects might strike the head on parts of the chamber or 

 on the framework above the chamber. The opening has therefore been 

 changed from the top to the front of the calorimeter chamber. It is fitted 

 with two panes of plate glass Avhich are easily manipulated and give a very 

 satisfactory closure. This change has been of great advantage, as the sub- 

 ject can very easily enter the chamber and sit in the chair without great 

 difficulty. In reconstructing the top slight alterations were made which give 

 somewhat more space for the shoulders and head, and while the total content 

 of the chamber has been increased but little, the advantages are considerable. 



RESPIRATION APPARATUS FOR MEN. 



In the last report mention was made of a respiration apparatus for the 

 determination of the respiratory quotient and of the respiratory exchange in 

 short periods, which had been developed and constructed in this laboratory. 

 While a considerable number of experiments had been made with it, it was 

 not by any means perfected in all minor details, and during the past year 

 another apparatus has been built on exactly the same principle as the pre- 

 vious one. This has been constructed more substantially and more carefully 

 finished, and a number of improvements made. The new apparatus waa 



