excursions and
found them delightful. But still more profitable to him were the long
and almost daily walks which he enjoyed with his teacher, during the
latter half of his time at Cambridge. Henslow's wide range of
acquirement, modesty, unselfishness, courtesy, gentleness, and piety,
fascinated him and exerted on him an influence which, more than anything
else, tended to shape his whole future life. The love of travel which
had been kindled by his boyish reading, now took a deeper hold of him as
he read Humboldt's "Personal Narrative" and Herschel's "Introduction to
the Study of Natural Philosophy." He determined to visit Teneriffe, and
even went so far as to inquire about ships. But his desire was soon to
be gratified in a far other and more comprehensive voyage. At the close
of his college life he was fortunate enough, through Henslow's good
offices, to accompany Sedgwick in a geological excursion in North Wales.
There can be little doubt that this short trip sufficed to efface the
dislike of geology which he had conceived at Edinburgh, and to show him
how much it was in his own power to increase the sum of geological
knowledge. To use his own phrase, he began to "work like a tiger" at
geology.

But he now had reached the main turning-point of his career. On
returning home from his ramble with Sedgwick he found a letter from
Henslow, telling him that Captain Fitz-Roy, who was about to start on
the memorable voyage of the Beagle, was willing to give up part of his
own cabin to any competent young man who would volunteer to go with him,
without pay, as a naturalist. The post was offered to Darwin and, after
some natural objections on the part of his father, accepted.

The Beagle weighed anchor from Plymouth on December 27, 1831, and
returned on October 2, 1836.

On his return to England, Darwin at once took his place among the
acknowledged men of science of his country. For a time his health
continued to be such as to allow him to get through a large amount of
work. The next two years, which in his own opinion were the most active
of his life, were spent, partly at Cambridge, and partly in London, in
the preparation of his "Journal of Researches," of the zooelogical and
geological results of the voyage, and of various papers for the
Geological and Zooelogical Societies. So keen was his geological zeal
that, almost against his better judgment, he was prevailed upon to
undertake the duties of honorary secretary of th