548 



Mr. F. B. Jewett \ on a New Method of 



resistance-coils carried on an asbestos-covered iron frame, 

 and ending in two heavy terminal wires cc, which pass out 



K*. 1. 



through the covers of both boxes ; the bulb d is supported on 

 a metal frame e, and constant circulation is maintained by 

 an electrically-driven fan /; g represents the stem of a 

 platinum thermometer. With this arrangement, and with 

 suitable regulation for the current, the temperature may 

 easily be kept constant at any desired point to within one or 

 two degrees *. 



The gas-bulb or reservoir (fig. 2) was of hard glass of 

 known cubical content, and had a capacity of about 2000 c.c. ; 

 proceeding from the bulb were two tubes, one a heavy 

 capillary and the other with an internal diameter of about 

 1 cm. 



* In one instance where the bath was used for calibrating a Beckmann 

 thermometer the temperature was held constant to 0°1 for fifteen 

 minutes. 



