From:
Sir John Herschel
To:
Unidentified
Date:
[1840 to 1841]
Source of text:
TxU:H/M-0407.2; Reel 1087
Summary:
Note on diurnal changes in [magnetic] variation at St. Helena and on estimated cost (£950) of observatory at St. Helena.
Contributor:
John Herschel Project