Excerpt from Supplementary Notes to the Atlas Stellarum Variabilium The positions of all the stars within the square 30' wide have been determined by means of a semicircular glass scale, divided into parts 3' wide, and of a chronograph. These positions are differential with regard to the Nova as zero point. From the preface to the Atlas, in which the details of this method are described, we only recall the statement that the Right Ascen sions are supposed to be correct within while the Declinations may be erroneous by or even 026. The positions of the stars outside this square have been computed from the bd. Or the ago., assuming the position of the Nova, given in the title of the chart, to be correct for the beginning of the year 1901. The magnitudes of all the stars on the chart were determined by sequences of steps, based on at least two independent estimates. The formula for: transforming these steps to the bd. Scale is of the same character as those in the Atlas. It will be an easy matter to replace it by any other process of transformation, graphical or arithmetical, when a scale of standard magnitudes is determined by photometric means. The faintest stars near the Nova could not be properly estimated on account of the brightness of the latter. It is well to remark that only three good nights (march 7, 14, 16) were available for making this chart, and that then the Nova was brighter than 4th magnitude. Yet it has seemed better to distribute chart and catalogue as they are without delay, in order to facilitate observation. A more accurate scale of magnitudes, for the final reduction of the observations, may be deter mined at any future time, when the brightness of the new star shall have faded away. 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.