those who "did not go in for honors," a not very remarkable class standing. He was still required to put in two years of residence, and during this interval he spent most of his time with Sedgwick in the study of geology in the field. Returning to his home after a geological trip into Wales, Darwin found awaiting him a letter from Henslow, offering him an appointment that opened to his ardent mind the door to a career after his own heart. The British nation, being the greatest commercial nation of the globe, has the greatest need for accurate charts of all the seas. Frequently she has sent out great charting expeditions to various parts of the world. One of these was to go out in Her Majesty's ship, _Beagle_, for a voyage around the world. Captain Fitzroy was in command, and he was especially commissioned to map the coast of South America from La Plata to Cape Horn and up the western side. In addition to this work, by carrying a set of accurate chronometers, he was to check up the longitude of the various ports to be visited in this circumnavigation of the globe. It was customary on such expeditions to carry a young man whose duty it was to study the natural history of the countries visited on the trip. The salary of such a naturalist was so small that an experienced man could scarcely afford to take the place. Therefore the appointment usually went to a man rather of promise than of achievement. Through Henslow's influence, Charles Darwin was offered this position in 1831. Darwin hastened to obtain his father's permission, but the elder Darwin at first declined to consider the matter. He felt that his son had not made such use of his time at the university as warranted the hope that much could be expected of such a journey. He believed it necessary that Charles should have some means of earning an adequate living before he could think of devoting his time to science. Charles found an efficient advocate in the person of his uncle, Josiah Wedgwood, Jr. Together they persuaded the father of the propriety of giving to Charles this opportunity to follow out his real tastes and ambitions. Accordingly, at the age of twenty-two, we find him embarked on a journey around the world. In the cabin of the _Beagle_ he had abundant time, in his long sail across the Atlantic, to read the two volumes of Lyell's "Elements of Geology," which Henslow had handed him, with the suggestion that he read it, but on no account believe it. Filled with the love of geology as Darwin was, this epoch-making book was exactly the stimulus needed. Lyell had just begun to persuade the world that to understand the past we must study the present. In the forces now at work he saw cause enough to account for all the history of the past of the earth.