"His lectures on botany were universally popular, and as clear as daylight. So popular were they that several of the older members of the University attended successive courses. Once every week he kept open house in the evening, and all who cared for natural history attended these parties, which, by thus favoring intercommunication, did the same good in Cambridge, in a very pleasant manner, as the scientific societies do in London.... This was no small advantage to some of the young men, as it stimulated their mental activity and ambition.... "During the years when I associated so much with Professor Henslow, I never once saw his temper even ruffled. He never took an ill-natured view of any one's character, though very far from blind to the foibles of others. It always struck me that his mind could not be even touched by any paltry feeling of vanity, envy, or jealousy. With all this equability of temper and remarkable benevolence, there was no insipidity of character. A man must have been blind not to have perceived that beneath this placid exterior there was a vigorous and determined will. When principles came into play, no power on earth could have turned him one hair's breadth.... "Reflecting over his character with gratitude and reverence, his moral attributes rise, as they should do in the highest character, in preëminence over his intellect." Through this noble friend, Darwin had the opportunity of taking a five years' voyage in the ship Beagle, as a naturalist. The bark, of two hundred and thirty-five tons, under command of Captain Fitz-Roy, was commissioned by government to survey Patagonia, Tierra del Fuego, the shores of Chili, Peru, and some islands in the Pacific, "and to carry a chain of chronometrical measurements round the world." Professor Henslow knew the captain, and recommended his young friend for the position. Darwin had read Humboldt's travels eagerly, and was delighted with the prospect of a journey like this. Dr. Darwin was opposed at first, but finally said, "If you can find any man of common sense who advises you to go, I will give my consent." Young Darwin at once visited his uncle, Josiah Wedgwood, at Maer, who approved of the journey, and soon convinced Dr. Darwin of the wisdom of it. The vessel sailed December 27, 1831. Though for a young man of an extremely affectionate nature the separation from family was painful, yet it was a glad day for Darwin. He had looked forward eagerly to it, saying, "My second life will then commence, and it shall be as a birthday for the rest of my life," and so it proved. He said, years afterward, "The voyage of the Beagle has been by far the most important event in my life, and has determined my whole career."