16 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



with a small fall in temperature, under precisely the same conditions of 

 stirring as those maintained in the foregoing experiments. In this way, 

 consistent results were obtained, the averages of which are recorded in 

 the curve (Figure 4). 



0.008° 



0.007° 



0.006° 



0.005° 



0.004' 



0.003' 



0.002° 



0.001 



10 

 Figure 4. 



20 



30 



Lag of Thermometer Employed in Foregoing Experiments. 



The time after the immersion of the slightly warmed thermometer is recorded 

 in the direction of abscissae in seconds ; the lag of the thermometer in the di- 

 rection of ordinates in 0.001° intervals. The curve represents the average of 

 many figures. Upon it are plotted the tangents corresponding to several rates of 

 cooling, expressed in fractions of a degree per minute. From these tangents comes 

 the table below. 



