From:
John Henry Dallmeyer
To:
Sir John Herschel
Date:
[23 December 1870]
Source of text:
RS:HS 6.8
Summary:
Has made a trial of JH's lens but it was too large to be satisfactory. Regarding the 'graphoscope,' a new toy. Has been concerned with the manufacture of an improved form of opera glass. Present forms have many imperfections. Gives details of his own theories and sends one for JH's notice.
Contributor:
John Herschel Project