io2 Proceedings. 



been filled with water at some temperature below 98 , a 

 current is sent through the platinum wire of such strength 



Fig-- 3- 



that the temperature ascends fairly rapidly to the required 

 temperature, this current strrength is then suddenly 

 reduced to an amount previously determined and chosen 

 so as to give a very slow and steady increase of temperature 

 in the inner vessel. This rise should not exceed o°'iF. per 

 minute, but it is essential that the temperature should con- 

 tinuously rise during the time of testing. As soon as the 

 temperature has thus been regulated the carrier is plunged 

 into the water. There is at first a cooling of the water due 

 to the introduction of the carrier, but the rise in temperature 

 soon begins to reassert itself. The cooling may, if desired, 

 be almost reduced to nothing, by keeping the carrier before 

 insertion into the testing vessel in water of about 90 , but 

 there is no particular object in thus complicating the 



