l introduction, which would appear to have led to the first
perusal of Hutton's great work, and that of his brilliant illustrator,
Playfair.

CHAPTER VI

'THE PRINCIPLES OF GEOLOGY'

We have seen that as early as the year 1817, when he visited East
Anglia, Lyell began to experience vague doubts concerning the soundness
of the 'Catastrophist' doctrines, which had been so strongly impressed
upon him by Buckland. And these doubts in the mind of the undergraduate
of twenty years of age gradually acquired strength and definiteness
during his frequent geological excursions, at home and abroad, during
the next ten years. At what particular date the design was formed of
writing a book and attacking the predominant beliefs of his
fellow-geologists, we have no means of ascertaining exactly; but from a
letter written to his friend Dr Mantell, we find that at one time Lyell
contemplated publishing a book in the form of 'Conversations in
Geology[42],' without putting his name to it. This was probably
suggested by the manner in which Copernicus and Galileo sought to
circumvent theological opposition in the case of Astronomical Theory.

But this plan appears to have been soon abandoned; and by the end of the
year 1827, when he had reached the age of thirty, Lyell had sent to the
printer the first manuscript of the _Principles of Geology_, proposing
that it should appear in the course of the following year in two octavo
volumes[43].

A great and sudden interruption to this plan occurred however, for just
at this time Lyell was engaged in writing his review for the _Quarterly_
of Scrope's work on _The Geology of Central France_, and while doing
this his interest was so strongly aroused by the accounts of the
phenomena exhibited in the Auvergne, that he was led for a time to
abandon the task of seeing his own book through the press; and, having
induced Murchison and his wife to accompany him, set off on a visit to
that wonderful district. He also felt that, before completing the second
part of his book, he needed more information concerning the Tertiary
formations, especially in Italy.

Lyell had been very early convinced of the supreme importance of travel
to the geologist. In a letter to his friend Murchison he said:--'We must
preach up travelling, as Demosthenes did "delivery" as the first, second
and third requisites for a modern geologist, in the present adolescent
state of the science[44].'

And Professor Bonney ha