14 BULLETIX 951, V. S. DEPAKTMEXT OF AGRICULTURE. 
The value of a continuous-temperature record in the process of 
incubating cultures is great. Such records are not only of vahie in 
showing the temperature at all times throughout the period of incu- 
bation, but they may be dated and filed for reference, thus making 
it possible to determine with accuracy the temperature maintained in 
the incubating process on any previous date. 
Fig. 11. — Chart showing the temperature maintained in the Incubating room of the 
Pathological Division, January 22 to 29, 1918. Note that night temperatures especially 
are practically without fluctuation. 
The chart in figure 11, taken from the incubator room equipped 
with the temperature-control system designed in the bureau, shows 
the temperature mamtained for the week January 22 to 29. 1918 — 
typical of the winter season. Attention is invited to the fact that 
during the night periods, when the room is closed, there is scarcely 
any variation in the temperature. During the day periods, however, 
when the door is opened for storing or taking out specimens, tem- 
perature variations occur. But in no instance do the variations 
exceed 1° C, and they exist for only a few minutes at a time. Even 
