208 WAKEEN UPHAM, M.A., F.G.S.A., ON THE NEBULAE AND 



craters quite resembling the moon's craters, but not on the extensive 

 scale of the moon's surface, although a number of the craters on 

 the moon's surface are small. 



With respect to the large question of the nebular hypothesis I 

 confess I must coincide with Mr. Tuckwell. It seems to me that 

 Laplace's idea of a heated nebular mass is quite out of the question 

 in cold regions of space. I quite conform to Mr. Chamberlin's 

 theory of the mass being elemental, as it were, and that these 

 atoms combined together would form molecular solids, and 

 thus we get ■ Mr. Chamberlin's original nebulae. These would 

 unite together and form a central nucleus, and attract more and 

 more of those surrounding them, and thus rapidly grow. 



With respect to the growth of the earth, as stated in this paper, 

 I really cannot follow Mr. Upham. He speaks of primitive 

 atmosphere when the earth was only half or less than half the size 

 that it is. There was a gradual growth of the earth from that 

 small mass to the greatness of a planet. In a nebula, such 

 as he assumes, a great number of small bodies that formed 

 one mass would be aggregated to a very considerable size. It 

 could draw and unite others and it would grow to its maximum 

 dimensions in a very short time. It would not require enormous 

 ages for bodies one after another to come into it, and it would 

 rapidly aggregate to itself all that was available for it, with the 

 exception of any small masses which are coming in down to the 

 present day. 



With regard to the volcanic hypothesis I must say that something 

 is wanting. The two writers seem to assume that the cause of 

 volcanic heat is internal heat, the central heat of the globe. I have 

 disputed that for a long time. It is practically impossible for 

 volcanic lava to come from 30 miles below the surface. It is 

 impossible for lava to penetrate through solid rocks for that distance ; 

 and lava is not due to the central heat of the globe. 



There is no mention in this paper of rock-fusing temperature 

 except this. This rock-fusing heat is induced by internal 

 heat, but when it produces the chemical action — which 

 again produces heat — you have a rock fusing temperature 

 obtained at a very short distance below the surface; and the 

 lava comes from a very short distance below the surface, three or 

 four miles at most. 



