242 Dr. H. A. Wilson on the Velocity of Solidification 

 Tube 0'2 centim. in diameter. 



Temperature 

 of Bath. 



Velocity of 

 Solidification. 



mms./min. 



34-3 1-10 



33-0 1-62 



30-0 2-88 



28-0 3-30 



27-0 3-23 



24-0 3-87 



23-5 3-88 



17-0 3-93 



11-5 4-13 



Fig. 1. — Velocity of Solidification of Salol. 



10 c 



These results are shown graphically in fig. 1. It will be 

 observed that the velocities are not the same at the same 

 temperatures in the two tubes ; but when the correction in- 

 dicated by the thermocouple is applied, the two curves 

 become approximately identical. The wider tube had thicker 

 walls than the narrower one, which of course would render 

 the escape of the heat developed more difficult in the wider 

 tube, which accounts for the greater rise of temperature found 

 in it. 



The effect on the velocity of surrounding the tube by a 



