Zones Of Stars Observed At The National Observatory Washington

Excerpt from Zones of Stars Observed at the National Observatory, Washington, Vol. 1: Part I, Containing the Zones Observed With the Meridian Circle in 1846 The value of a revolution of the micrometer screw has been obtained from the intervals of 4 3 and 4 5. 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.

The following zones of stars were observed with the Transit Instrument in the years, 1846, 1847, 1848, and 1849, and form the complement of the zones observed with the Mural Circle in the same years; it having been the intention that the Transit Instrument should furnish for the reductions the standar right ascensions and the Mural Circle the standard declinations.

The zones of stars contained in the following pages were observed with the Meridian Circle in the years 1847, 1848, 1849, and form a continuation of those reduced and published by Mr. James Ferguson, assistant astronomer, in the year 1860. The zones reduced by Mr. Ferguson are those which were observed with this instrument in the year 1846. In his introduction Mr. Ferguson has given a description of the Meridian Circle, and a detailed account of the methods of making and reducing the observations. The description of the instrument will be found also in the annual volume for 1846, page XXXVII. The object-glass of the telescope was 4.5 inches in aperture, and 58.2 inches in focal length. The diaphragm contained eleven transit wires, and sever micrometer-wires for declination. The transit wires were designated 1, 2, I, II, III, IV, V, VI, VII, 10, 11; and the micrometer wires 1, 2, 3, 4, 5, 6, 7. The first of the transit-wires was that first passed by a star, circle east ; and the first of the micrometer-wires was that uppermost in the field, circle east, and the observer looking southward.