Zone d'identification
Cote
Add. MS a/204/8
Titre
James David Forbes to George Peacock
Date(s)
- 10 Nov. 1832 (Production)
Niveau de description
Pièce
Étendue matérielle et support
3 pp
Zone du contexte
Nom du producteur
Histoire archivistique
Source immédiate d'acquisition ou de transfert
Zone du contenu et de la structure
Portée et contenu
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.