From:
Edward Sabine
To:
Sir John Herschel
Date:
19 June [1840]
Source of text:
RS:HS 15.326
Summary:
[Charles] Riddell's observations suggest Europe and North America experience magnetic disturbances at similar times, but in opposite directions. Suggests course of action for [Charles] Riddell and Lieutenant Younghusband in North America.
Contributor:
John Herschel Project