Just before this, in 1856, Maxwell, though only twenty-five years of age, was offered the chair of natural history, which included most of the physical sciences, at Marischal College, Aberdeen. With the attention that his mathematical papers attracted, it is not surprising that after four years of teaching experience he was invited to King's College, London. He held his new position for eight years, and then his health required him to retire to his estate in Kirkcudbrightshire. After three years of retirement, his English Alma Mater demanded his services, and the temptation to get back to an academic career was so great that he could not resist it. He became, in 1871, Professor of experimental physics at Cambridge. To him, more than to anyone else, is due the magnificent development of the physical sciences which took place at Cambridge during the last quarter of the nineteenth century. Unfortunately, he was not destined to live to enjoy the fruits of his labor in organizing the scientific side of the university, but it was under his direction that the plans of the Cavendish Laboratory were prepared, and he superintended every step of the progress of the building. It was under his careful management, too, that the purchase of the very valuable collection of apparatus, with which it was equipped by the Duke of Devonshire, was made, and Maxwell's work here counts for much in the history of English science. He died in 1879, when only forty-eight years of age, but he had deeply impressed himself upon the science of the nineteenth century. For quite one-half of his scant half-century span of life he had occupied a prominent place in England, and after the age of thirty-five had come to be generally recognized as one of the leading physical scientists of the world. His career is, as we have said, a striking illustration of how early in life a man's real work is likely to come to him, and how little success in original investigation is dependent on that development of mind which is supposed to be due only to long years of application to a particular branch of study. Manifestly it is the original genius that counts for most, and not any training that it receives, except such as comes from its own maturing powers. Environment, if unfavorable, does not hamper it much, nor keep it from reaching the proper terminus of its destiny; and poor health only serves to prevent the exercise of its full powers, but does not eclipse the manifestation of its capacity.