Reference numberAP/12/15/2
TitleUnpublished letter, regarding the northwest magnetic pole from John Macdonald to Sir Humphry Davy
Date19 October 1825
DescriptionMacdonald details his process for calculating the approximate location of the northwest magnetic pole. Includes a diagram of the earth viewed from the South Pole, indicating a possible location for the southeast magnetic pole. He writes that he worries that if the British do not begin making concerted efforts to discover the true locations of these poles, the French or Russians might achieve it first.

An ink inscription at top of first page reads '(JFWH [John Frederick William Herschel]. No 74)'.

Subject: Geodesy

Written by Macdonald in Summerlands, Exeter [Devon, England].
Physical descriptionInk on paper
Access statusOpen
Related records in the catalogueAP/12/15
Fellows associated with this archive
NA8200Davy; Sir; Humphry (1778 - 1829); chemist1778 - 1829
NA3036Macdonald; John (1759 - 1831)1759 - 1831
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