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John Churchman on magnetic variation and finding the longitude, 1787 - 1804

Reference Code: GBR/0180/RGO 14/42: 56-141

Scope and Contents

From the File:

Correspondence regarding the effects of magnetic variation on the mariner's compass, the use of magnetic variation to establish longitude and the cause of magnetic variation.


  • Creation: 1787 - 1804


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 (


95 folio(s) (95 ff.) : Paper

Language of Materials



Churchman, John

Original geographic information

London [destination]

Original geographic information

Philadelphia [origination]

Finding aid date

2011-12-17 10:58:35+00:00

Repository Details

Part of the Cambridge University Library Repository

Cambridge University Library
West Road
Cambridge CB3 9DR United Kingdom