Catalogue of Stars for the Epoch Jan, 1, 1892

Catalogue of Stars for the Epoch Jan, 1, 1892
Catalogue of Stars for the Epoch Jan, 1, 1892
Excerpt from Catalogue of Stars for the Epoch Jan, 1, 1892: Stars 1892 From Observations by the Great Trigonometrical Survey of India From ObservationsFor the effective prosecution of a geodetic survey, it is indispensable that the latitudes and longitudes of a certain number of the principal stations of the triangulation should be obtained from astronomical observations, independently of their values as computed from the triangulation. The great accumulation of observed zenith distances of stars for latitudes, and of observed transits for longitudes in the geodetic survey of India, gave rise to the conviction that the material thus laboriously collected might be utilized for compiling a star catalogue, a conviction which has resulted in the publication of the accompanying list of star-places for January, 1892, with the necessary constants for the reduction of their places to other epochs.In order that the method by which the latitude and longitude observations were employed in the construction of the catalogue may be understood, a few introductory remarks seem necessary.To begin with the Right Ascensions. These are purely differential, that is to say they are obtained by measurement of the difference of Right Ascension of the catalogued star and of some adjacent Nautical Almanac star observed with it; the latter being considered for the purposes of this Catalogue as errorless. For convenience of reference the name of the comparison Nautical Almanac star or stars thus employed is entered in the fifth column of the Catalogue.In determining differences of longitude in India with the help of the electric telegraph, the method adopted as being the most direct and trustworthy was to record at both stations, by one and the same clock, the times of transit of certain stars at intervals of from one to three minutes, arranged in groups of eight or ten. The clock at the eastern station was employed first, and when two groups of stars had passed, the clock at the western station was similarly used. During the passage of each group the whole apparatus remained in statu quo, excepting only the necessary change in altitude of the transit telescope, so that when all corrections for collimation, level, and azimuth have been made, the interval between the transits of any two stars at either station represents the difference of their right ascensions. Each station furnishes a record of this description. As it is obvious that only approximate star places are required when this method is adopted, B.A.C. stars were freely used; for the differences of longitude depend solely upon the time occupied by a star passing from the meridian of the eastern, to that of the western observer.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.Эта книга будет изготовлена в соответствии с Вашим заказом по технологии Print-on-Demand компанией ООО «Книга по Требованию». Print-on-Demand - это технология печати книг по Вашему заказу на цифровом типографском оборудовании. Книга, произведенная по технологии Print-on-Demand (POD) представляет собой классическую печатную книгу с соблюдением всех стандартов качества, от офсетной бумаги и плотного картона до качественного клея, используемого при изготовлении. Черно-белая текстовая или полноцветная иллюстрированная книга (в зависимости от исходного файла, подготовленного к печати) может быть изготовлена в разных вариантах: - в мягкой обложке (Клеевое Бесшвейное Скрепление); - скрепление скобой (для книг с небольшим количеством страниц); - в твердом переплете с клееным текстовым блоком; Материалы, используемые при производстве книги: - бумага текстового блока - офсетная (белая или кремовая) 80 г/м2 - мягкая обложка - бумага мелованная 250 г/м2; - ламинация обложки - матовая или глянцевая; - твердый переплет - картон 2 мм, каптал, белые форзацы, прямой корешок - сверхпрочный полимерный клей; - каждая книга упакована в термопленку. Каждый заказ обрабатывается в индивидуальном порядке: каждой книге, напечатанной по технологии Print-on-Demand, присваивается уникальный номер.