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SILSBEE AND HONAMAN: CONDUCTIVITY MEASUREMENTS 



(3) The path over the rim of the cup for any surface leakage is rela- 

 tively long. 



(4) A satisfactory contact can be made between the specimen and 

 the electrodes by immersing the bottom of the cup in a conducting 

 fluid (in these experiments melted solder) and by inserting some of this 

 fluid inside the cup to form the upper electrode. 



These specimens were used in the furnace shown in figure i. 



Fig . I . Electric furnace as used in conductivity measurements . 



The heating coil inserted in the plug below the specimen was found 

 necessary to compensate for the flow of heat through the bottom 

 of the furnace. By proper adjustment of the relative amounts 

 of current through the main winding and through this additional 

 coil, the temperatures inside and outside the cup could be equal- 

 ized. These temperatures were measured by two copper con- 



