From:
Edward Sabine
To:
Sir John Herschel
Date:
[8 October 1840]
Source of text:
RS:HS 15.106
Summary:
Actinometers for [Louis] Agassiz and John Caldecott are ready. Asks if JH wants to compare them to his standard instrument. Excessive magnetic disturbances in May were found simultaneously in Göttingen and Toronto, but the curves do not correspond.
Contributor:
John Herschel Project