88 



Mr. R. J. Moss, 



to the maximum production of vapour. Mr. Stoney's explana- 

 tion not only removes this anomaly, but demands the compara- 

 tively low temperature of the spheroid as an essential condition 

 of the phenomenon, since the existence of the layer of polarized 

 air or vapour by which the spheroid is supported, requires the 

 proximity of a cool surface, in order that the velocity of the 

 gaseous molcules moving from this surface may be much less 

 than that of the molcules which move towards it from the adja- 

 cent hot surface. 



Mr. Stoney suggested to me the possibility of maintaining 

 spheroids on liquid surfaces of the same substance by ensuring 

 that the floating drop shall continue cooler than the liquid under- 

 neath, and by otherwise removing the causes which occasion its 

 shipwreck. Commercial ether readily adapts itself to the re- 

 quired conditions. After a series of experiments I have adopted 

 the arrangement shown in the figure as one which successfully 

 accomplishes the desired objects. 



u 



yJ 



A thin glass tube about 15 mm. in diameter and 12 cm. long 

 having a spout-like limb about 7 mm. in diameter and 7 cm. in 



