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<rdf:Description rdf:about="https://catalogues.royalsociety.org:443/CalmView/record/catalog/AP/12/10" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/">
  <dc:title>Unpublished paper and letter, 'Description of a machine for perpetuating motion' by Joseph Hopkins</dc:title>
  <dc:description>Hopkins describes his design for a perpetual motion machine consisting of a wheel with a groove for a ball bearing, balanced on pivots and supported by pillars. Includes figures of the machine in the text. Followed by a letter from Hopkins to the John Frederick William Herschel.

Subject: Physics

Received by the Royal Society on 20 November 1826.</dc:description>
  <dc:date>17 November 1826</dc:date>
</rdf:Description>