Excerpt from Astronomical Observations Made at the Observatory of Cambridge, Vol. 22: For the Years 1866, 1867, 1868, and 1869 The Transit Observations were all made by Mr Graham (g), with the exception 'of a few taken in 1866 by Mr S. G. Graham (s): the Circle Observations are all by Mr Todd (t); The Transit Instrument and the Mural Circle, as well as the methods employed in observing with these Instruments, have been fully described by Professor Challis in the introductions to previous volumes of the Cambridge Observations, and more recently in his Lectures on Practical Astronomy, Cambridge, 1879. An elaborate account of the. Northumberland Equatorial has been given by the Astronomer Royal in a separate publication; and in the Introduction to Vol. XI. Of the Cambridge Observations for 1838, pp. Xi - xiii Professor Challis has given a sufficient description of this instrument to render the Observations made with it intelligible, he has also given an admirable account of it.iri his Lectures. The Square Bar Micrometer is described at some length in the Introduction to vo]. XXI. 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.

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