i86 
Journal of Agricultural Research 
Vol XXVI, No. 4 
lated brine tank is controlled by a thermostat immersed in the brine 
and acting to start and stop the refrigerating machine on a temperature 
variation of approximately 3 0 F. The electric motor operating the 
brine-circulating pump is also started and stopped automatically by a 
thermostat located in the coil room. By this means the temperature 
in the coil room is held within a variation of 3 0 F. 
WIRING DIAGRAM 
A complete wiring diagram of the temperature-control system for the 
indoor portion of the indoor plant is illustrated in figure 2. As originally 
installed, no heating coils or fans were provided in the different rooms; 
subsequently these auxiliaries were installed in an attempt to get a closer 
temperature control. Ordinary desk fans were placed in the rooms for 
the purpose of stirring up the air. The heating coils were employed for 
heating back to the desired temperature; that is, the thermostat con¬ 
trolling the flow of the cooling medium was adjusted to give a temperature 
slightly below that desired and the heating coils operated to bring the 
temperature up to the desired point. Very little, however, was gained 
by the employment of these auxiliaries. 
TYPICAL TEMPERATURE CHARTS 
Typical temperature charts are illustrated in figure 3. The upper 
chart shows the variation in temperature of the outside air covering a 
period of one week, while the middle chart shows the temperature main- 
