From:
William Rutter Dawes
To:
Sir John Herschel
Date:
[27 May 1857]
Source of text:
RS:HS 6.104
Summary:
Is grateful for the copy of his Essays. Query about measuring the focal length of a double object glass. Gives results of his recent observations. Hopes accounts of JH's son are good.
Contributor:
John Herschel Project