[Illustration: FIG. 23
Temperature recorder. The recorder with the coordinate paper in the
lower box with a glass door. A curve representing the temperature
difference between the ingoing and outgoing water is directly drawn on
the coordinate paper. Above are three resistance boxes, and the switches
for electrical connections are at the right. On the top shelf is the
galvanometer, and immediately beneath, the plug resistance box for
altering the value of certain shunts.]
[Illustration: FIG. 24.--Detailed wiring diagram showing all parts of
recording apparatus, together with wiring to thermometers complete,
including all previous figures.]
The whole apparatus is permanently and substantially installed on the
north wall of the calorimeter laboratory. A photograph showing the
various parts and their installation is given in fig. 23. On the top
shelf is seen the galvanometer and on the lower shelf the recorder with
its glass door in front and the coordinate paper dropping into the box
below. The curve drawn on the coordinate paper is clearly shown. Above
the recorder are the resistance-boxes, three in number, the lower one at
the left being the resistance S_{1}, the upper one at the left being the
resistance S', and the upper one at the right being the resistance
Z_{1}. Immediately above the resistance-box Z_{1} is shown the plug
resistance-box which controls on the one hand the resistance _r_ and on
the other hand the resistance S, both of which are substantially altered
when changing the apparatus to register from the 0° to 4° scale to the
0° to 8° scale. A detailed wiring diagram is given in fig. 24.