re Perraudin could find any one who treated his notion
with greater respect. Then he found a listener in M. Venetz, a civil
engineer, who read a paper on the novel glacial theory before a local
society in 1823. This brought the matter once more to the attention of
De Charpentier, who now felt that there might be something in it worth
investigation.

A survey of the field in the light of the new theory soon convinced
Charpentier that the chamois-hunter had all along been right. He became
an enthusiastic supporter of the idea that the Alps had once been
imbedded in a mass of ice, and in 1836 he brought the notion to the
attention of Louis Agassiz, who was spending the summer in the Alps.
Agassiz was sceptical at first, but soon became a convert.

In 1840 Agassiz published a paper in which the results of his Alpine
studies were elaborated.

"Let us consider," he says, "those more considerable changes to which
glaciers are subject, or rather, the immense extent which they had in
the prehistoric period. This former immense extension, greater than any
that tradition has preserved, is proved, in the case of nearly every
valley in the Alps, by facts which are both many and well established.
The study of these facts is even easy if the student is looking out for
them, and if he will seize the least indication of their presence; and,
if it were a long time before they were observed and connected with
glacial action, it is because the evidences are often isolated and occur
at places more or less removed from the glacier which originated them.
If it be true that it is the prerogative of the scientific observer to
group in the field of his mental vision those facts which appear to be
without connection to the vulgar herd, it is, above all, in such a case
as this that he is called upon to do so. I have often compared these
feeble effects, produced by the glacial action of former ages, with the
appearance of the markings upon a lithographic stone, prepared for the
purpose of preservation, and upon which one cannot see the lines of the
draughtsman's work unless it is known beforehand where and how to search
for them.

"The fact of the former existence of glaciers which have now disappeared
is proved by the survival of the various phenomena which always
accompany them, and which continue to exist even after the ice has
melted. These phenomena are as follows:

"1. Moraines.--The disposition and composition of moraines enable them
t