From:
George Biddell Airy
To:
Sir John Herschel
Date:
[23 April 1856]
Source of text:
RS:HS 1.229 (C: RGO 6.216.114)
Summary:
Wants one or more of JH's actinometers. Notes his suggestion about the zenith tube.
Contributor:
John Herschel Project
Wants one or more of JH's actinometers. Notes his suggestion about the zenith tube.