Excerpt from Catalogue of Double Stars, From Observations Made at the Royal Observatory, Greenwich: With the 28-Inch Refractor During the Years 1893-1919 For systems in which the relative motion has as yet been too small for the determination of orbit elements, it is possible to form an estimate of the parallax. 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.