58 
OROGENY AND EARTH’S ROTATION 
ulation could be fixed, such reference is not so strange. Although 
they do not necessarily supplant it the divers later or alternative 
explanations of orographic genesis at least emphasize the frailty 
of the once sole theme. 
With the recent establishment of new view-angles of the prop¬ 
erties of matter, our old notion concerning the condition of the 
interior of the earth instead of remaining settled for all time un¬ 
dergoes complete transformation. The contractional hypothesis 
not only looks askance for substantiation; but its very antithesis 
perhaps finds today stronger support. In view of these condi¬ 
tions the contractional hypothesis may be advantageously and 
critically examined anew before it is finally accepted with the 
complacency that it at one time enjoyed. Alone Joly’s startling 
suggestion shakes to its nethermost foundations the notion of a 
collapsing earth. 
In its ultimate analysis the cubical expansion idea of orogeny 
appears to be only a special or local phase of the broader astron¬ 
omical conception of a cooling globe. Its basic proposition calls 
for exceptionally heavy deposition, the excessive weight of which 
depresses the earth’s crust locally, or regionally, into the hotter 
interior. The process is necessarily one of such extreme slowness 
that it is difficult to understand how depression and upward ex¬ 
pansion can go on contemporaneously. It must be premised that 
the sedimentation is completed before any notable rise in tem¬ 
perature takes place which is probably seldom or never the case. 
As it is advocated by T. Mellard Reade, its most recent support¬ 
er, the rock-expansion hypothesis is really only an amplification of 
the old Huttonian idea advanced a century before, that continental 
upheaval is due to the localized effects of subterranean heat. 
Hutton, followed by Babbage, Lyell and Dana, considered the 
expansion only in vertical or linear direction; whereas Reade 
treats it in three dimensions. 
Following some of the American geologists Reade presumes, as 
a necessary condition of local rock-expansion and mountain up¬ 
rising, an unusual development of the clastic column. More¬ 
over the process is regarded as possible only in areas of excep¬ 
tionally thick sedimentation. Although mountain-building and 
excessive sedimentation should therefore appear occurring to¬ 
gether they find curious coincidence only in few places, as, for 
