Zona de identificação
Código de referência
Add. MS a/204/8
Título
James David Forbes to George Peacock
Data(s)
- 10 Nov. 1832 (Produção)
Nível de descrição
Item
Dimensão e suporte
3 pp
Zona do contexto
Nome do produtor
Entidade detentora
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Fonte imediata de aquisição ou transferência
Zona do conteúdo e estrutura
Âmbito e conteúdo
Geneva - Thanks GP for all his suggestions prior to his trip abroad. The letters Lord Palmerston favoured him with have been most useful - especially in avoiding the Prussian custom house. He has been taking many observations in the Alps with his Magnetic and Meteorological apparatus: concentrating on magnetic intensity at heights. To eliminate the effect of temperature on his results he has been conducting experiments on the needles in question at different temperatures. Using John Herschel's actinometer he has taken observations - 'at stations separated by a vertical column of 6500 feet of air' - to determine the loss of force of the solar rays in passing through the atmosphere. Sends his regards to WW and George Airy.