ADJUSTMENT OF TEMPERATURE 135 



This water-vessel is fitted water-tight outside the plant- 



Fig. 37. Arrangement for Variation of Temperature. The 

 Plant- vessel with Bubbler seen to the right; outer enclosing 

 Vessel v seen to the left 



Level of water up to definite mark m adjusted by the funnel F. 

 Variation of temperature produced by flew of warm water 

 from the cylinder c ; attainment of constant temperature 

 is assured when the thermometer inside the plant-vessel 

 indicates the same as the second thermometer in the outside 

 vessel v. 



vessel, and communicates with a cylinder c, with a non- 

 conducting jacket of felt, which contains warm water at 



