Excerpt from Monthly Notices of the Royal Astronomical Society, Vol. 23: Containing Papers, Abstracts of Papers, and Reports of the Proceedings of the Society, From November 1862, to June 1863; Being the Annual Half-Volume of the Memoirs and Proceedings of the Royal Astronomical Society At Prof. Smyth's request I have appended one or two foot notes to his communication, as, from the circumstance of his present temporary residence in the country, his access to original authorities has been necessarily limited. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.