D. Trowbridge on the Nebular Hypothesis. 345 
THE THEORY, 
1. GroLoey has revealed the fact that it took immense ages 
of time to form the earth, and fit it for the habitation of man. 
he same science also oints, somewhat definitely, to a ti 
when the earth was in a highly heated condition. Mathematical 
view, is derived from the physical constitution of Comets, 
rations, perhaps 
action." As the 
Operations of heat become less and less potent. 
I. Of Stellar Systems. 
tation respecting the existence of any such nebulous mass, even 
if such a body now exists within the range of telescopic vision, 
as IT have attempted to show in a former paper in this Journal. 
Cannot define ol. xxxvii, [2], p. 210. 
_* Chemical action should not be left out of the consideration, but at present we 
unot define its operations so well. Vi oe 
Ax. Jour. Sct.—Srconp Sextes, Vou. XXXVIII, No, 114.—Nov., 1864. 
: 44 
* 
