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The Royal Society: Science in the Making

Letter, from Henry Oldenburg to Jean Cassini, dated at London

Reference number: EL/O2/55

Date: 26 August 1671

Description

That Brouncker had been shown Cassini's paper on the sunspots; encloses pages of Boyle's observations of the sunspots made in 1660; concerning Huygens' 'Systema Saturnium'; concerning observations of the occultation of Saturn by the moon by Hevelius; postscript that Monsieur Picard had observed the sunspots in 1661 and that some English astronomers had just observed a sunspot on 25 August 1671

Reference number
EL/O2/55
Earliest possible date
26 August 1671
Page extent
3 pages
Format
Manuscript
Also available on Early Modern Letters Online
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Creator names

Henry Oldenburg

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Henry Oldenburg

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Citation

Henry Oldenburg, Henry Oldenburg, Letter, from Henry Oldenburg to Jean Cassini, dated at London, 26 August 1671, EL/O2/55, The Royal Society Archives, London, https://makingscience.royalsociety.org/items/el_o2_55/letter-from-henry-oldenburg-to-jean-cassini-dated-at-london, accessed on 23 June 2025

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  • Early Letters

    The archival collection known as 'Early Letters' is composed of original manuscript letters sent to, or collected by, the Royal Society from English and foreign correspondents.

    Dates: 1613 - 1740

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