ast from the manner in which it is expressed; for perhaps
at bottom our opinions upon this subject do not differ much.

M. de Saussure says that the formation of this valley depends upon the
mountains themselves, and not upon the erosion of the rivers. I agree
with our author, so far as the mountains may have here determined the
shape and situation of the valley; but, so far as this valley was
hollowed out of the solid mass of our earth, there cannot be the least
doubt that the proper agent was the running water of the rivers. The
question, therefore, comes to this, How far it is reasonable to conclude
that this valley had been hollowed out of the solid mass. Now, according
to the present theory, where the strata consolidated at the bottom of
the sea are supposed to be erected into the place of land, we cannot
suppose any valley formed by another agent than the running water upon
the surface, although the parts which are first to be washed away, and
those which are to remain longest, must be determined by a concurrence
of various circumstances, among which this converging declivity of the
strata in the bordering mountains, doubtless, must be enumerated.

With regard to any other theory which shall better explain the present
shape of the surface of the earth, by giving a cause for the changed
position of the strata originally horizontal, I cannot form a judgment,
as I do not understand by what means strata, which were formed
horizontally, should have been afterwards inclined, unless it be that of
a power acting under those strata, and first erecting them in relation
to the solid globe on which they rested.

Besides, in supposing this valley original, and not formed by the
erosion of the rivers, What effect should we ascribe to the transport
of all those materials of the Alps, which it is demonstrable must have
travelled through this valley? Whether is it more reasonable to
suppose, on the one hand, that the action and attrition of all the hard
materials, running for millions of ages between those two mountains, had
hollowed out that mass which originally intervened; or, on the other,
that this valley had been originally formed in its present shape, while
thousands of other valleys have been hollowed out of the solid mass?

But to put this question out of doubt, with regard to this very valley
of the river _Doire_, M de Saussure has given us the following decisive
fact, Sec. 881: "Immediatement au-dessus de cette source