96 



VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



RESPIRATION CHAMBER. 



Personal visits to Stockholm and Helsingfors and inspection of both 

 the Scandinavian chambers led to material modification in the design 

 for the chamber built in the Nutrition Laboratory. Thus it was seen 

 that the height could easily be reduced. Second, the entrance to the 

 chamber was best made from the top; fortunately the unusually high 

 ceiling of the calorimeter laboratory made this change possible without 

 difficulty. The calorimeter laboratory is provided with excellent auto- 

 matic heating and cooling arrangements for maintaining uniform tem- 

 perature. Hence no special appliances for heating the new respiration 

 chamber were needed. As a matter of fact, it was found subsequently 

 that cooling rather than heating was absolutely essential. 



Fig. 6. — ^View of east end of group respiration chamber. 



a, Inner wooden floor; 61 and bi, windows; c, suspension-rod supporting roof of chamber; d, step- 

 ladder; e, hook for supporting ladder d when not in use; /, trap-door resting in groove gg when 

 closed; hh, brine coil; k, rotary air impeller; b, opening into chamber for ingoing air; m, Bun- 

 sen burner for heating ingoing air; n, butterfly valve. 



The details of construction of the respiration chamber are given in 

 figures 6 and 7. Figure 6 shows the window (east) end of the chamber. 

 A cross-section of the chamber in the longest dimension from west to 

 east is represented in figure 7. 



The respiration chamber has an inner lining of sheet metal, which is 

 absolutely air-tight. As this inner fining required a substantial wooden 

 backing to prevent unnecessary wear or play by the buckling of the 

 sheet metal, a framework was built on the floor of the calorimeter room 



