218 STORRS AGRICULTURAL EXPERIMENT STATION. 

chamber, for regulating the temperature of the ingoing air, for preventing the 
passage of heat through the walls of the apparatus, and for measuring the quan- 
tities of heat given off by the body and carried out by the water current. 
If to these is added a very brief account of the methods for measuring the 
volume of the ventilating air current, and for determining the composition before 
and after it has passed through the chamber, little more need here be said 
regarding the apparatus and methods of its use. 
A general idea of the apparatus can be had from figures g and io. Figure g,. 
from a photograph, is a general view of the principal parts of the apparatus, 
though the pump and aspirators used for moving, measuring and sampling the 
ventilating air current, and the refrigerating machine are not shown. In the 
center is the large chamber which is surrounded by sheathing of wood. At 
the end of the chamber, on the right, is shown a glass door which serves also as. 
a window. In the foreground, near the center and at the right, are the pipes. 
through which the ventilating current of air passes. At the right of the win- 
dow and just below it are the arrangements for cooling and for measuring 
the current of water which brings away the heat from the interior of the cham- 
ber. At the left, in front of the large brick pillar, is a table at which an 
observer sits to record the temperature of the interior of the apparatus and of 
the currents of air and water, these temperatures being measured by electrical 
thermometers, Behind the brick pillar is the refrigerating machine, not shown. 
in the picture. The object of this is to cool the brine, z. ¢., a solution of calcium 
chloride contained in a large tank in the center foreground. The tank is sur- 
rounded by a wooden casing. The ventilating current of air, before it enters. 
the chamber, is passed through copper cylinders which are immersed in brine 
in this tank, and thus cooled to a temperature of from —1g9 to —22 degrees. 
Centigrade, or from —2 to —8 degrees Fahrenheit. At this very low tempera- 
ture nearly all of the water is removed from the air, so that it enters the 
chamber quite dry. Just before entering, at the right of the glass door, it is. 
warmed to the temperature of the interior of the chamber. On coming out it 
passes once more through copper cylinders in the cold brine, and thus the 
larger part of the water which has been imparted to it by the respiration of 
the man inside the chamber is frozen and removed. The air pump is at the . 
right and the aspirators are at the left of the position occupied by the camera 
in taking the photograph. 
THE RESPIRATION CHAMBER. 
The internal construction of the chamber and the arrangements for regulating 
the temperature are shown in horizontal section in figure Io, 
The chamber proper is practically an apartment with double walls of metal, 
the inner wall being of sheet copper and the outer one of zinc. ‘The interior is. 
2.15 m. (7 ft.) long, 1.92 m. (6 ft. 4 in.) high, and 1.22 m. (4 ft.) wide, the 
corners being rounded. It thus has a little less than 28 square feet of floor 
space. The cubic content is not far from 4.8 cubic meters or 175 cubic feet. 
The inner wall is made of large sheets of copper, the seams being soldered so. 
that when the windows and other openings are closed the chamber is air tight, 
and the only air which enters or leaves is that of the ventilating current. Out- 
side this copper wall is one of zinc. Between the two metal walls is an air 
space (A) of 7.5 cm. (3 in.). In this Space stands a wooden frame work to 


