Two books greatly influenced Darwin—Herschel’s “Introduction to the Study of Natural Philosophy,” which, he said, “stirred up in me a burning zeal to add even the most humble contribution to the noble structure of Natural Science”; and Humboldt’s “Personal Narrative,” which roused in him the longing to travel—a desire which was soon afterwards gratified by his voyage in the Beagle.
“Upon the whole,” he says, “the three years which I spent at Cambridge were the most joyful in my happy life; for I was then in excellent health, and almost always in high spirits.”
After passing his last examination, Darwin had still two terms’ residence to keep, and was advised by Henslow to study geology. To this end Henslow asked Sedgwick to allow Darwin to go with him on a geological excursion in North Wales in August, 1831. He thus gained experience which was of the utmost value during the voyage of the Beagle.
CHAPTER III.
VOYAGE OF THE “BEAGLE” (1831–36).
About the time of the excursion with Sedgwick (the exact date is uncertain) Professor Henslow received a letter from George Peacock (formerly Dean of Ely and Lowndean Professor of Astronomy at Cambridge) stating that he had the offer to recommend a young man as naturalist to accompany Captain Fitzroy on a surveying expedition to many parts of the world. Leonard Jenyns (afterwards Blomefield) was evidently considered to be the most suitable person for the position, but he was unable to accept it. Henslow at once wrote (August 24th, 1831) to Darwin, and advised him to do his utmost to obtain the position, and Darwin found the letter waiting for him on his return home after the geological excursion with Sedgwick. As his father greatly disliked the idea, Darwin at once wrote (August 30th) and declined, and the next day went to Maer to be ready for the shooting on September 1st. Here, however, his uncle, Josiah Wedgwood, took a very different view from that adopted by his father, with the result that both he and Darwin wrote (August 31st) to Shrewsbury and reopened the question. Darwin’s letter shows the most touching deference to his father’s wishes, and the gravest apprehension lest he should be rendered “uncomfortable” or “uneasy” by any further suggestion as to the possibility of the voyage, although his father had said, “If you can find any man of common-sense who advises you to go, I will give my consent.” We also learn from the “Autobiography” that his uncle sent for him whilst out shooting and drove him the thirty miles to Shrewsbury, in order that they might talk with his father, who then at once consented. This must have been on September 1st, 1831.
From this time until he went to Plymouth, on October 24th—the final start was not until December 27th—his letters show that he had a very busy time making purchases and preparing for the voyage. These letters breathe the warmest affection to the members of his family and his friends, together with the keenest enthusiasm for Captain Fitzroy, the ship, and the voyage.
The voyage of the Beagle lasted from December 27th, 1831, to October 2nd, 1836. Darwin says that it was “by far the most important event in my life, and has determined my whole career.... I have always felt that I owe to the voyage the first real training or education of my mind” (l. c., p. 61). He attributes the greatest share in this training to geology, among the special sciences, because of the reasoning involved in making out the structure of a new and unknown district; but he considers that the habits of “energetic industry and of concentrated attention” which he then acquired were of the utmost importance, and the secret of all his success in science. He tells us that the love of sport was present at first in all its keenness, but that he gradually abandoned it for scientific work.
Among his numerous observations and discoveries during the voyage, those which appear to stand out in his mind so that he quotes them in his “Autobiography” are—the explanation of the forms of coral islands, the geological structure of St. Helena and other islands, and the relations between the animals and plants of the several Galapagos islands to each other and to those of South America. His letters and the collections which he sent home attracted much attention; and Sedgwick told Dr. Darwin that his son would take a place among the leading scientific men. When Darwin heard this from his sisters, he says, “I clambered over the mountains of Ascension with a bounding step, and made the volcanic rocks resound under my geological hammer.” His letters during the voyage are full of enthusiasm and of longing to return to his family and friends.
There was the same conflict between the naval and scientific departments of the Beagle on the untidiness of the decks which was afterwards repeated on the Challenger, where I have been told that one of the naval authorities used to say, with resigned disgust, “Oh, no, we’re not a man-of-war, we’re only a —— dredger!”