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Description: | P.29" (Period of oscillation 29 seconds) 17.3 Grams (written in black ink on the reverse of the bezel, probably the weight with the needle or bearing). Makers armorial Trade Mark "NEW -ERA", MODEL- E. DES THOMSON,William,Lord,1st Baron Kelvin of Largs. after 1876 MANU Whyte Thomson & Co Glasgow Scotland This card appears to be a production model of one of two forms of the dry card. The two types are: form a, which has the needle assembly suspended below the plane of the card and form b which has the needle assembly above the plane of the card. In this type form a, the platinum-irridium needle could have been: either supported above the nave of the card pointing downwards through the plane of the card and supported on a sapphire bearing or visa versa. The two groups of four fine steel needle magnets suspended on green silk threads below the plane of the card are arranged in parallel rows on either side of the nave. The paper bezel is supported by a thin aluminium ring and 32 radial green silk threads attached to the nave which consists of a fine, pierced aluminium disc. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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