IN coming before you this evening my first duty is to announce the death of Prof. William Chauvenet. This sad evént was not unexpected, since, at the time of his election to the presidency of the Association, at the close of our meeting at Salem in August 1869, it was already feared that failing health would prevent him from meeting with us at Troy, in 1870. This, as you are aware, was the case, and I was therefore called to preside over the Association in his stead. In the autumn of 1869, he was compelled by illness to resign his position of Chancellor of the Washington University of St. Louis, and in December last died at the age of fifty years, leaving behind him a record to which Science and his country may point with just pride. During his connection of fourteen years with the Naval Academy at Annapolis he was the chief instrument in building up that institution, which he left in 1859 to take the chair of Astronomy and Mathematics at St. Louis, where his remarkable qualities led to his selection, in 1862, for the post of Chancellor of the University, which he filled with great credit and usefulness up to the time of his resignation. It is not for me to pronounce the eulogy of Prof. Chauvenet, to speak of his profound attainments in astronomy and mathematics, or of his published works, which have already taken rank as classics in the literature of these sciences. Others more familiar with his field of labour may in proper time and place attempt the task. All who knew him can however join with me in testifying to his excellences as a man, an instructor, and a friend. In his assiduous devo'ion to scientific studies he did not neglect the more elegant arts, but was a skilful musician, and possessed of great general culture and refinement of taste. In his social and moral relations he was marked by rare elevation and purity of character, and has left to the world a standard of excellence in every relation of life which few can hope to attain.