CALORIMETER LABORATORY. 9 



supply and return which go through the floor to the basement. The tem- 

 perature control of this room is therefore very satisfactory and economical. 

 It is not necessary here to go into the advantages of temperature control 

 of the working rooms during the summer months. Every one seems to be 

 thoroughly convinced that it is necessary to heat rooms in the winter, but 

 our experience thus far has shown that it is no less important to cool the 

 laboratory and control the temperature and moisture during the summer 

 months, as by this means both the efficiency and endurance of the assistants, 

 to say nothing of the accuracy of the scientific measurements, are very 

 greatly increased. Arduous scientific observations that would be wholly 

 impossible in a room without temperature control can be carried on in this 

 room during the warmest weather. 



