IO8 A RESPIRATION CALORIMETER. 



uprights at one end (6, b~) are grooved to fit the inner walls ; those at 

 the other end (c, c) are rectangular in cross-section. All four up- 

 rights are well painted to prevent absorption of moisture and conse- 

 quent warping, such precaution being especially necessary because of 

 the location of the laboratory in the basement of a stone building. 



Extending between these uprights in both directions, at the top and 

 bottom of the structure, are joists ; those extending across the shorter 

 dimension are shown in cross-section in figure 24 (a, a and 6, ), and 

 those running lengthwise in figure 23 (a, a and b, b} . These eight joists 

 and the four uprights form a rigid support for the wooden walls. 

 Like the two uprights b, b, shown in figure 8, the two joists a, a, shown 

 in figure 24, are grooved to receive the inner wooden partition. 



The floor of the outer wooden structure rests upon two pieces of 

 cedar 15 by 15 cm. , shown in cross-section (c, c, in fig. 24), which are laid 

 directly upon the laboratory floor. These hold the ends of the floor of 

 the outer casing firmly against the lower edges of the joists a and b. In 

 addition to these there are nine large blocks (d, d, d, in figs. 23 and 24) 

 placed under the cleats of the floor at the points where the weight of 

 the calorimeter is supported ; that is, under the castors on which it stands. 

 Between the floor ot the outer and that of the inner wooden structure 

 are smaller blocks (c, c, fig. 23, and e, <?, <?, fig. 24), upon which rest 

 the cleats of the inner wooden floor, these cleats being directly under 

 the castors. 



All other parts of the walls, floors, and ceilings of both inner struct- 

 ures are securely fastened to the joists and uprights above described, 

 but in such manner that when necessary they may be easily removed 

 so as to render all parts of the outside of the calorimeter accessible. 

 To facilitate the removal, each wall, ceiling, or floor is constructed as a 

 panel, from matched hard pine, screwed together with a number of 

 cleats and battens, as illustrated in figures 23 and 24. The outer panels 

 are provided with metal handles sunk into the wood for convenience 

 in removing them. In spite of the large size of the panels (the smallest 

 being 1.62 by 2.24 meters), none of them shows evidence of warping 

 after having been used over three years. Matched boards were used to 

 avoid cracks, which would afford opportunity for the diffusion of air. 



Of the eight panels forming the sides and ends of the two wooden 

 structures, six are readily removable. The other two, namely, those 

 at the end in which the window is built, may also be removed if neces- 

 sary, but to take out the outer panel in this end involves considerable 

 trouble in disconnecting apparatus adjacent to it on the outside. The 

 occasions for removing this panel, however, are very rare. Even in 



