From:
Sir John Herschel
To:
John Tyndall
Date:
[16 November 1864]
Source of text:
RS:HS 17.396 (C: RI 532 & RS:HS 24.68))
Summary:
Surprised that JT cannot obtain heat spots [see JT's 1864-11-14]. Describes glasses and lenses used.
Contributor:
John Herschel Project