772 On the Evidence that the Earth's Interior is Solid. (August, — 
We cannot imagine that matter so rigid as the earth's interior 
is claimed to be, could yield to the pressure of sediments, glaciers 
or lava flows, as has been advocated. This view is based chiefy 
on the fact that areas of thick detrital formations must have been 
areas of subsidence, hence, it is argued, the deposit itself has 
been the cause of the sinking. The reverse appears rather to be 
true, that only areas of extended subsidence can be areas of gret 
deposition. May it not then be claimed that the subsidence was 3 
the cause of the deposition instead of the deposition being the 
cause of the subsidence; and is not the former view more 
than the latter ? 
The deposition of sediment in any locality requires that one 
portion of the earth’s crust should be lower than another. la | 
the theory of a solid globe this would be brought about by the l 
„elevation of a portion of the crust, while in the theory of a liquié | 
globe by the depression of a portion of that crust. 
In a viscous mass, such as the earth’s interior next the crust ® 
here supposed to be, coupled with the irregular thickness of the 
crust, no especial connection could be expected to exist betwee d 
different vents, even if near one another, until after the lapse of : 
considerable time — the viscidity itself preventing any rapid 
motion of the interior mass. 
Whatever water was met, on the welling up to the sutface of 
the lava, would naturally render the latter more liquid, 5° wa d 
-it entered into the lava. The intervention of water ina yor’ 3 
eruption seems to be mainly its action on the lava during 4 
passage upwards, instead of its being the cause of ed 4 
It, indeed, plays a striking rôle in volcanic phenomena, gt q 
does not seem to be the primum mobile. It is difficult to hee 
lava in ascending to the earth’s surface could reach it sik 
meeting water somewhere on its way. When the water Dos 
could the results be different from those now witnessed? "i 
it not seem that water is the accident rather than the ad 4 
the eruption, and do not most observers transform an effect q 
a cause ? é 4 
_ It may be said that the physical evidence advanced in bebat : 
of its essential solidity is violated by the premises and while 
_ chosen as the basis of the mathematical discussion; ™” B 
 petrographical and geological facts demand either a8 interior 
is liquid or one that can readily become so. 
