146 STORRS AGRICULTURAL EXPERIMENT STATION. 
The apparatus as set up for the combustion is shown in figure 2. 
M is the calorimeter cylinder. Those employed by Berthelot and 
Stohmann are made of brass. We have found the ordinary “ white 
metal” used in making silver plated ware, which is essentially an | 
alloy of tin, copper and antimony, well adapted to the purpose. 
This is large enough to hold the bomb and two liters of water, 
the water rising just to the top of the valve screw and very near 
to the top of the cylinder. LL is a stirrer which is moved up and 
down and thus brings the water to. a uniform temperature. The 
calorimeter cylinder is contained in two larger concentric cylin- 
ders. In the apparatus as used by Berthelot and by Stohmann 
these are made of copper. ‘They may be so joined that the 
space between the inner and outer one can be kept filled with 
water and thus effectually | 
prevent the passage of heat 
from without inward. We 
have used cylinders of ordi- 
nary indurated fiber, N and 
O, with air spaces between. 
The indurated fiber is a 
good non-conductor of heat 
. and we have found the 
arrangement satisfactory. 
Each of the two cylinders 
has a cover of vulcanized 
Z rubber. Beneath and on 
Fic. 3.—Cross SECTION OF ‘Bows CaLorimerer the sides of the calorime- - 
gaa ter cylinder are supports 
of cork which keep it in place and prevent contact with cylinder 
N. The vulcanized rubber covers are each provided with two 
small holes through which pass the two upright rods of the 
stirrer and a larger hole for the thermometer P. In the sides of 
the two cylinders N and O near the top are holes through which 
pass wires H and I, to connect the platinum wires H and I with 
an electric battery. The whole apparatus is shown in cross sec- 
tion in figure 3. In this one of the flat, horizontal rings of the 
stirrer L is shown. ‘This is wide enough to nearly fill the space 
between the bomb and the cylinder, but has a number of holes 
so that when it is moved up and down the water is not unduly 
agitated. One side is cut away to make room for the ther- 
mometer. 




