Outlines of astronomy / By Sir John F.W. Herschel.

  • John Frederick William Herschel
Date:
1849
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of astronomy / By Sir John F.W. Herschel. Source: Wellcome Collection.

    17/730 (page 9)
    CONTENTS. PREFACE - - - - - - Page iii—vii. INTRODUCTION = “ : - % T PART I. CHAPTER I. General notions. Apparent and real motions. Shape and size of the Earth. The horizon and its dip. The atmosphere. Refraction. Twi- light. Appearances resulting from diurnal motion. From change of station in general. Parallactic motions. Terrestrial parallax. That of the stars insensible. First step towards forming an idea of the distance of the stars. Copernican view of the Earth’s motion. Relative motion. Motions partly real, partly apparent. Geocentric astronomy, or ideal reference of phenomena to the Earth’s centre as a common conventional station - - - : > - 10 CHAPTER II. Terminology and elementary geometrical conceptions and relations. Ter- minology relating to the globe of the Eartfi—to the celestial sphere. Celestial perspective - - - - > - 57 CHAPTER IIt. Of the nature of astronomical instruments and observations in general. Of sidereal and solar time. Of the measurements of time. Clocks, chronometers. Of astronomical measurements. Principle of telescopic sights to increase the accuracy of pointing. Simplest application of this principle. The transit instrument. Of the measurement of angular intervals. Methods of increasing the accuracy of reading. The vernier. The microscope. Of the mural circle. The Meridian circle. Fixation of polar and horizontal points. ‘The level, plumb- line, artificial horizon. Principle of collimation. Collimators of Rittenhouse, Kater, and Benzenberg. Of compound instruments with co-ordinate circles. The equatorial, altitude, and azimuth instrument. Theodolite. Of the sextant and reflecting circle. Principle of re- _ petition. Of micrometers. Parallel wire micrometer. Principle of the duplication of images. The heliometer. Double refracting eye-piece. Variable prism micrometer. Of the position micrometer mtn fe: