|Title||Unpublished letter, regarding magnetic variation and structure of the earth from John Macdonald to Sir Humphry Davy|
|Date||30 November 1826|
|Description||Macdonald writes to correct an error in a letter sent on 12 June 1826 (AP/12/15/6). Davy discusses observations by explorers of magnetic variation as well as theories of the internal structure of the earth. Includes a figure showing the presumed location of the northwest magnetic pole in relation to northeast line of no variation.|
Minor corrections appear in ink. Below the date, an ink inscription reads 'N. T.Y. [Thomas Young]'.
Written by Macdonald in Summerlands, Exeter [Devon, England].
|Physical description||Ink on paper|
|Related records in the catalogue||AP/12/15|
Fellows associated with this archive
|NA8200||Davy; Sir; Humphry (1778 - 1829); chemist||1778 - 1829|
|NA3036||Macdonald; John (1759 - 1831)||1759 - 1831|