From:
Sir John Herschel
To:
Sir John [Richardson]
Date:
[30 December 1847]
Source of text:
WT 67597.4
Summary:
[Responding to JR's 1847-12-28], JH gives advice where to buy actinometers and what features to look for. JH cannot advise about hygrometers as these are to be used in very cold climates.
Contributor:
John Herschel Project