626 PROCEEDINGS OF THE AMERICAN ACADEMY. 



No great confidence should be placed in the numerical accuracy 

 of this indication, but the direction of the change seems to be well 

 established. 



The cause of the apparent increase in conductivity of the packing, 

 both at 100° and at 218°, with lapse of time is not known. 



The value here found for f, combined with that found for the same 

 coefiicient when asbestos packing was used, gives as a mean 

 f = - ^ (0.00076 + 0.00060) = - 0.00068. 



