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The Royal Society: Science in the Making

Unpublished letter, regarding parallel lines and the sum of angles from J [John] Walsh to J F W [John Frederick William] Herschel

Reference number: AP/11/24

Date: 10 January 1824

Description

Walsh writes that he found [Humphry] Davy's commendation of mathematics and the work of [John] Brinkley gratifying as a mathematician. Walsh explains that in his paper he shows that the sum of the three angles of every plane triangle is equal to two right angles, independently of parallel lines. He provides an example of this rule in the letter. This is a covering letter for AP/11/25.

An inscription in brown ink at the top right corner of the first page reads '(35 JFWH [John Frederick William Herschel])'.

Subject: Mathematics

Written by Walsh in Cork [Ireland].

Reference number
AP/11/24
Earliest possible date
10 January 1824
Physical description
Ink on paper
Page extent
3 pages
Format
Manuscript

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Citation

Unpublished letter, regarding parallel lines and the sum of angles from J [John] Walsh to J F W [John Frederick William] Herschel, 10 January 1824, AP/11/24, The Royal Society Archives, London, https://makingscience.royalsociety.org/items/ap_11_24/unpublished-letter-regarding-parallel-lines-and-the-sum-of-angles-from-j-john-walsh-to-j-f-w-john-frederick-william-herschel, accessed on 12 February 2026

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https://makingscience.royalsociety.org/items/ap_11_24/unpublished-letter-regarding-parallel-lines-and-the-sum-of-angles-from-j-john-walsh-to-j-f-w-john-frederick-william-herschel

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    The 'Archived Papers' collection is comprised of original manuscript scientific papers and letters submitted to the Royal Society which remained unpublished or were abstracted in the journal 'Proceedings of the Royal Society' published from 1830 onwards.

    Dates: 1768 - 1989

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