From:
Warren de La Rue
To:
Sir John Herschel
Date:
[26 June 1861]
Source of text:
RS:HS 6.148
Summary:
Gives diameter of the sun's image. Used an ordinary eye-piece. There must be some mistake about the penumbra. It is possible now to take daily records of the surface of the sun.
Contributor:
John Herschel Project