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<rdf:Description rdf:about="https://catalogues.royalsociety.org:443/CalmView/record/catalog/HS/16/348" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/">
  <dc:title>Letter, from Sir John Herschel to Mary Somerville, dated at Collingwood</dc:title>
  <dc:description>Autograph letter signed by sender. John Frederick William Herschel sending papers on his actinochemistry (photography). Discusses [James] Forbes's viscosity theory, nebulae of Southern Hemisphere. Explains his photographic processes Cyanotype and Amphytype and promises to send to Mary Somerville Robert Hunt's upcoming book. Asks Mary Somerville if she can guide someone to testify on functions of De Vico's great refractor at Collegio Romano. The monks at Collegio Romano will not allow Mary Somerville to do it herself. John Frederick William Herschel would trust [William] Somerville judgement. Discusses Lord Rosse's telescopes, and observation of the [De Vico?] comet in Halifax (Nova Scotia), and comments on politics in England.</dc:description>
  <dc:date>17 March 1844</dc:date>
</rdf:Description>