602 Prof. Bankine and Mr. Smith on the Viscosity of 



other a wider tube containing a pellet o£ mercury which 

 forces the gas in the apparatus through the capillary. It is 

 illustrated in fig. 1, surrounded by a steam-jacket. This 

 viscometer lias been modified in one respect since it was 

 used for determinations with the inert gases, viz , in the 

 mode of introducing the steam into the jacket. The steam 



Fig-, l 





S 



\J 



was always admitted at the top of the apparatus, when in -a 

 vertical position, and escaped by both exits. This probably 

 gave a more uniform temperature than had been realized 

 before. 



The method of observation was also modified in one 

 important particular. Preliminary measurements gave rise 

 to the suspicion that the three gases under investigation 

 produced very considerable alterations in the surface tension 



