In reviewing the literature, we were unable to find any continuous temperature studies made on a series of premature infants. Isolated instances have been reported, but a constant twenty-four hour record has not heretofore, as far as we could determine, been carried out. Such a record has been made possible through the cooperation of Leeds, Northrup Company, who remodeled their temperature resistance recorder so that it came in the range of human temperatures.1
The recording instrument is a self-balancing Wheatstone bridge (fig. 1). In one arm of the Wheatstone bridge is placed a resistance thermometer which has the property of changing resistance with temperature (fig. 2). By suitable selection of the resistance material for the resistance winding of the thermometer, it is possible to calibrate the scale of the recording instrument directly in temperature.
The range of the recorder which is used for the measurement of body temperature is