W. B. Rogers on Rotating Rings of Air and Liquids. 255. < ‘ 
ing column, combining with the upward impulsion of the in- 
_ terior will, therefore, give rise to a similar rotation of the cloudy 
‘mass, rolling it up into the spirally constructed ring in which it ~ 
presents itself at the close of the explosive action. 
t will be remarked that these explosive rings are more rapid | 
their expansion as well as their rotation than the rings pro- 3 
ueed by mechanical discharge, a result due doubtless to the 
greater energy of the forces by which they are developed. As 
_ might be expected, rings of the latter kind approach more nearly 
_ tothe former in these particulars when a vigorous impulse is 
_ applied in producing them. : 
n most cases the wreath of phosphoric acid is so opaque as 
5 Phe 
Soe 
; + : . . % d 
of ae easily in a Se parks ae a . 
inch in length, has a smoothh ! 
