From:
Sir John Herschel
To:
Humphrey Lloyd
Date:
1839-3-[15 or earlie
Source of text:
RS:HS 25.14.20
Summary:
Passes on the suggestion, from G. B. Airy, of the use of copper rings for damping the movements of measuring instruments in measuring terrestrial magnetism.
Contributor:
John Herschel Project