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Papers on the Thompson 28-inch Equatorial Telescope, 1882 - 1920

Reference Code: GBR/0180/RGO 7/37

Scope and Contents

'Observations for the determining of the focus of the South East Equatorial for different rays', 1882-1888.

Sixteen undated pages of calculations titled 'Correction of chromatic aberration for photographic rays by convex flint lens and concave crown lens placed within principal focus'.

Undated sheet of calculations on the separation of the lenses of an object glass.

Three undated sheets of calculations on the correction of an object glass for photographic rays by the separation of the lenses.

Four sheets of undated calculations giving general formulae for corrections.

Notes and diagrams by Christie titled 'on a corrector for adapting an ordinary object glass to photography'.

Rough notes on 'Heath's Optics', 1887.

Seven pencilled sheets of undated calculations on the double corrector for 'Photo-Rays'.

'Photo object glass - Flint lens in front.'

Notes on Herschel's form of object glass, undated.

Correspondence with E.W. Maunder on the difficulty of turning the South East Dome.

Notes on the water clock.

Correspondence with Sir Harry Thompson concerning the gift of a 9" photo-object glass and a 9" prism, 1890.

Correspondence with Dr A.A. Common regarding the manufacture of a new 3 foot mirror, 1890.

Correspondence with Sir Howard Grubb regarding the proposal to fit a new clock and electric control to the Lassell Equatorial Telescope, and correspondence with Miss J. Lassell concerning modifications to the Lassell Equatorial Telescope, 1890.

Correspondence with Troughton and Simms concerning the fitting of an adaptor to the Sheepshanks Equatorial Telescope, 1890.

Estimate from E. Challis and Son for a cover for the Cooke Equatorial Telescope, 1887.

Miscellaneous correspondence regarding the Equatorial Lassell and Astrographic Telescopes, 1885-1891.

List of the weight of additions to the Lassell Telescope, 1886.

Note of an examination of the Merz 12¾" Telescope, 1893.

Correspondence concerning the Sheepshanks Equatorial Telescope, 1893.

Correspondence with T. Maw supplying information for an article on 'The Power required to Drive Telescopes', with a rough draft of the article, 1893.

List of drawings of the South East Equatorial received from Messrs Ransomes, Sims and Jeffries, 1893.

Correspondence with Troughton and Simms on the following subjects, 1893-1894: 1. Fittings for the 28" Telescope; 2. Differential chain tackle; 3. Slow motion clamps; 4. Alterations to the position micrometer; and 5. New eyepieces.

Correspondence with Sir Howard Grubb on the 28" Telescope object glass and the replacement of a broken mirror, 1894.

Miscellaneous memoranda concerning the Thompson Equatorial Telescope, 1897-1900.

Correspondence with Troughton and Simms concerning various minor repairs and adjustments to the 28" Refractor, 1900-1905.

Miscellaneous correspondence concerning repairs and queries relating to the 28" Equatorial Telescope, 1907-1920.

Correspondence with Troughton and Simms on the following subjects, 1908-1912: 1. New eyepiece for the Merz Refractor; 2. Position micrometer; 3. Convex mirror; 4. Rotating occulting sector; and 5. New cell for object glass.


  • Creation: 1882 - 1920


Conditions Governing Access

From the Management Group:

Unless restrictions apply, the collection is open for consultation by researchers using the Manuscripts Reading Room at Cambridge University Library. For further details on conditions governing access please contact Information about opening hours and obtaining a Cambridge University Library reader's ticket is available from the Library's website (


1 bundle(s) (1 bundle)

Language of Materials


Former / Other Reference


Finding aid date

2006-03-30 10:40:31+00:00

Includes index.

Repository Details

Part of the Cambridge University Library Repository

Cambridge University Library
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Cambridge CB3 9DR United Kingdom