When Dr. Peters and myself met in Paris in April 1887, we had some long conversations on the subject. He told me he did not intend to visit England, and it was agreed that I Should investigate all the sources of information possessed in the libraries there, and I particularly undertook to examine the Greek Selden Alma gest at Oxford, and several Arabic manuscripts, and send him the results. In this and the following year many letters and discussions passed between us. In a letter dated August 14, 1888, received by Dr. Peters August 25, I asked what steps he had taken towards publication, and considering the contributions I had made from the manuscripts in this country, I asked How far he would like, and would think it right, that my name Should be associated with his as a joint author? But I assured him I was quite single-minded in the matter, and that my interest was removed from any idea of a personal character. This letter remained unanswered, probably because no Steps had been taken towards preparing any part of the work for publication. On July 18, 1890, Dr. Peters died. It is unnecessary here to give an account of his life, which has been so fully dealt with in the addresses delivered on that occasion by Dr. Isaac H. Hall and Professor Oren Root, and in the pages of the monthly notices of the Royal Astronomical Society. On September 3, 1890, I addressed a letter to the executors of Dr. Peters, asking to be informed in what state his work on the Almagest remained with reference to publication and requesting that the manuscripts might be sent to me to complete, and on November 9, I891, all of his manuscripts and notes relating to this work, with some important exceptions, were sent to me.