SCIENCE AND TRAVEL--THE VOYAGE OF THE BEAGLE Sir Charles Lyell, in his _Principles of Geology_, the first edition of which appeared in 1830-1833, says: "If it be true that delivery be the first, second, and third requisite in a popular orator, it is no less certain that travel is of first, second, and third importance to those who desire to originate just and comprehensive views concerning the structure of our globe." The value of travel to science in general might very well be illustrated by Lyell's own career, his study of the mountainous regions of France, his calculation of the recession of Niagara Falls and of the sedimentary deposits of the Mississippi, his observations of the coal formations of Nova Scotia, and of the composition of the Great Dismal Swamp of Virginia--suggestive of the organic origin of the carboniferous rocks. Although it is not with Lyell that we have here principally to deal, it is not irrelevant to say that the main purpose of his work was to show that all past changes in the earth's crust are referable to causes now in operation. Differing from Hutton as to the part played in those changes by subterranean heat, Lyell agreed with his forerunner in ascribing geological transformations to "the slow agency of existing causes." He was, in fact, the leader of the uniformitarians and opposed those geologists who held that the contemporary state of the earth's crust was owing to a series of catastrophes, stupendous exhibitions of natural force to which recent history offered no parallel. Also enlightened as to the significance of organic remains in stratified rock, Lyell in 1830 felt the need of further knowledge in reference to the relation of the plants and animals represented in the fossils to the fauna and flora now existing. It is to Lyell's disciple, Charles Darwin, however, that we turn for our main illustration of the value of travel for comprehensive scientific generalization. Born, like another great liberator, on February 12, 1809, Darwin was only twenty-two years old when he received appointment as naturalist on H.M.S. Beagle, about to sail from Devonport on a voyage around the world. The main purpose of the expedition, under command of the youthful Captain Fitzroy, three or four years older than Darwin, was to make a survey of certain coasts in South America and the Pacific Islands, and to carry a line of chronometrical measurements about the globe. Looking back in 1876 on this memorable expedition, the naturalist wrote, "The voyage of the Beagle has been by far the most important event in my life, and has determined my whole career." In spite of the years he had spent at school and college he regarded this experience as the first real training or education of his mind.