in Cortlandt Street nine years before, my hard luck of having had no earlier training. Many an American college student of physics bemoaned in those days his lack of early laboratory training. When I say this I am touching the principal point of my narrative; it is the point at which my narrative begins to sail on the back of a wave which started actually when Johns Hopkins University was organized, in 1876, but the motive power of which had been gathering long before that, perhaps at the same time when the motive power of the Cambridge movement in favor of scientific research was gathering, resulting, as it had, in the establishment of the Cavendish Laboratory. But I must resume the thread of my story and return later to the point just mentioned. My lack of what Barnard called “knowledge of visible things ... acquired by the learner’s own conscious efforts ...” gave me much anxiety; and I often thought that it would, perhaps, be better to go to some other university where the director of the physical laboratory was an older man, who would not notice my age as much as would the new and extremely young director of the Cavendish Laboratory. That thought, however, did not console me much, because I was very much attached to Cambridge and did not wish to give up what my mother called “life among the saints of Cambridge.” Just then, as if by an act of kind providence, a letter from President Barnard of Columbia College reached me, enclosing a letter of introduction to John Tyndall, the famous physicist, colleague and successor of Faraday in the direction of the Royal Institution. Barnard informed me that Columbia had received a generous sum of money from Tyndall, representing a part of the net proceeds from his famous course of public lectures on light, which he had delivered in the United States in 1872-1873; that the income of this sum would be given as a fellowship to a Columbia graduate to assist him in his study of experimental physics; that the fellowship would be called a John Tyndall Fellowship, netting over five hundred dollars annually; and that he and Rood, professor of physics at Columbia, considered me a suitable candidate. Unexpected things of this kind happen every now and then, and when they do they certainly encourage the belief that there is such a thing as luck.