From:
Sir John Herschel
To:
Warren de La Rue
Date:
[7 November 1861]
Source of text:
RS:HS 23.346
Summary:
Thanks for pictures of Mars; speculates on the atmospheres of some planets.
Contributor:
John Herschel Project
Showing 1–4 of 4 items
Thanks for pictures of Mars; speculates on the atmospheres of some planets.
Sending him his first photograph of the sun's spot. Has caused a lot of preparation. Comments on various points.
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.
Is pleased that JH likes his plates of Mars. Has a great collection of drawings of Mars but only a few of Venus. Hopes by the Spring to have the photoheliograph working. Has just completed his volume on the eclipse for 1860.