REPORT ON GEOLOGY. 
401 
the primordial granite; lie points out also the general relations 
existing between the granitic axis of the mountain chains, the 
lines of elevation and dislocation of the strata, &c. ; and the 
lines of the actual volcanic craters in countries where such still 
continue active ; or, where these are absent, the points marked 
by the kindred phsenomena of earthquakes and thermal springs; 
concluding that from these relations it is impossible to propose 
as explanatory of volcanic ph sen omen a any probable theory, 
which does not at the same time embrace the entire structure 
of the globe in all its generality. 
Viewing the question of volcanic agency under these general 
relations, the problem of the proper temperature of our globe 
as emanating from some central source demands our first at¬ 
tention. The Essay of Cordier* on this subject is at once the 
most extensive and exact; and Fourvier has also illustrated this 
important subject, which has been well termed “ the fundamental 
basis on which a rational system of geology must rest,'' by the 
careful application of his general theory of heat. The observa¬ 
tions of Fox in our own Cornish mines have been among the 
best data supplied to this investigation. 
The inquiries instituted by Elie de Beaumont concerning the 
prevailing lines of direction f in which the principal European 
chains of mountains have been elevated, and the epochs at 
which the disturbing forces have acted in the disruption of the 
terraqueous crust, have also afforded the first example of an 
attempt to generalize some of the most important phenomena 
above alluded to by Von Bucli; but on the details of this theory 
and its application to the phenomena of our own island, I am 
called upon to report at length to the geological section of our 
own general body { ; and I shall only now observe that while 
I warmly admire the powerful grasp of mind which it displays, 
I must still consider many of its principles as rather locally 
than generally applicable; the wide extent embraced by its ge¬ 
neral enunciation will undoubtedly require much modification; 
and the unguarded manner in which the entire elevation of 
chains like the Alps appears to be referred to a single convulsion, 
* The same author had previously supplied us with our most accurate in¬ 
formation on the constitution and varieties of actual volcanic products. 
f De Beaumont’s theory on the general direction of our lines of stratification 
may suggestto us another recent attempt of M. Necker to point out a relation 
between these lines as indicated by the general outline of our continental masses 
and the lines of equal magnetic intensity, ( Biblioth.Univ . 1830). Should there 
prove to be any foundation for such a theory, it ought undoubtedly to be brought 
into connexion with Fox’s observations on the electro-magnetic phaenomena 
developed by the metalliferous lodes of Cornwall, &c. 
X This Report will be found in the Annals of Philosophy for July 1832, 
2 c 
