Unpublished letter, regarding the magnetic pole from John Macdonald to Sir Humphry Davy Macdonald asks that Davy acknowledge receipt of his letter and provide comments as he sees fit. He reports that he will be writing a paper on the variation of the compass for the Encyclopaedia Metropolitana. He writes briefly about contemporary voyages in the Americas and the Bering Strait in particular, and asks that the Royal Society recommend that efforts be made to determine the precise locations of the northwest and southeast magnetic poles. He then reports on magnetic experiments of his own and praises Davy's discovery of the diminution of oxidation of copper on the bottoms of ships. Subject: Geodesy Written by Macdonald in Summerlands, Exeter [Devon, England]. 28 September 1825