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RO and RGO Solar Plates Contact Prints, 1873-06-02 - 1972-08-02

Reference Code: GBR/0180/RGO 51

Scope and Contents

The 1873-1917 prints in this class were made from glass plate negatives which are no longer extant. The plates were the product of a solar observation programme begun in 1873 at the Royal Observatory, Greenwich but are thought to have been destroyed in the First World War. The sequence of images is a continuation of RGO 67: Kew Observatory solar photographs (1858-72) and is itself continued by RGO 50: Royal Observatory Greenwich and Royal Greenwich Observatory, Herstmonceux Solar Plates (1918-79).
The 1955 prints are of images made at different times of day from the plates in RGO 50 and thus do not replicate that series. The 1956-72 prints were made from plates extant in RGO 50. Gaps in the sequence of RGO 50 were filled by sourcing plates from other observatories and thus the prints in RGO 51 also include some images created in locations other than Greenwich and Herstmonceux.
From the early 20th century the prints show the hand drawn circles, arrows and reference codes made on the glass plate negatives to mark sun spots and foculae.


  • Creation: 1873-06-02 - 1972-08-02


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 (

Biographical / Historical

Please refer to the introduction to RGO 50 for a description of the rationale for solar observation by the RO and RGO and also of the process used to create the glass plate negatives from which these contact prints were made.


7437 photographic print(s) (7437 contact prints) : photograph

Language of Materials



Items previously classed as RGO 51/8001-8245 are now classed as RGO 202/1-245, those as RGO 51/8301-8400 are now classed as RGO 51/7238-7337 and those as RGO 51/8401-8490 are now classed as RGO 51/7338-742727.

Physical Characteristics and Technical Requirements

The 1886 and 1892-4 prints from India are in poor condition.

Other Finding Aids

A handlist is kept in the Manuscripts Reading Room but contains a considerable number of keying error rectified in this electronic version. A tabulated catalogue, combined with other RGO solar image lists, and which may be sorted by various data e.g. former reference.

Immediate Source of Acquisition

Produced or accumulated by the Royal Observatory, Greenwich and the Royal Greenwich Observatory. Prints dated from 1917 and from the 1950-70s are later additions to the class.

Related Materials

The source negatives of many of these contact prints are to be found at classmark RGO 50, RO and RGO Solar Plates. Further records of solar observations can be found in RGO 57, Kew Observatory sunspot observations; RGO 58, Heinrich Samuel Schwabe: sunspot drawings; RGO 64, RGO Solar Department: papers; RGO 65, RGO Herstmonceux Solar Records: Lyot filter negative films; RGO 81, Observations of the minor planet Eros to determine the solar parallax: papers and records; RGO 138, RGO Solar Eclipse Plates and Photographs; RGO 143, Royal Observatory, Cape of Good Hope Solar Records: Lyot filter negative films and records; RGO 144, Stonyhurst College and Zurich Observatories: sunspot drawings; RGO 157, RGO Solar Observation Records (including photoheliograph registers); RGO 169, Royal Observatory and RGO Solar Eclipse expeditions: records; and RGO 202, Ely Observatory Solar Plates Contact Prints: from Canon William Selwyn's observatory.


An article drawing on research on the solar images by D.M. Willis, V.N. Davda, and F. Richard Stephenson and entitled ''Comparison between oriental and occidental sunspot observations'' appeared in the Quarterly Journal of the Royal Astronomical Society, 37: p189–229 (Blackwell: Oxford, 1996).


The online catalogue for Janus was largely compiled from an existing list in June 2009 by Zoe A. Rees, Department of Manuscripts and University Archives.

Date information

DateText: 1873-1917; 1955-72.


Royal Observatory, Greenwich; Royal Greenwich Observatory, Herstmonceux

Finding aid date

2009-06-15 15:13:29+00:00

Repository Details

Part of the Cambridge University Library Repository

Cambridge University Library
West Road
Cambridge CB3 9DR United Kingdom