| Reference number | AP/12/15/5 |
| Level | Item |
| Title | Unpublished letter, regarding magnetic variation in Cape Horn from John Macdonald to Sir Humphry Davy |
| Date | 18 January 1827 |
| Description | Macdonald writes about an east variation of the magnetic needle observed near Cape Horn [Tierra del Fuego, Chile] on its west, south, and east sides, which he believes is caused by the local attraction of magnetic strata. Includes a figure illustrating this phenomenon.
John Frederick William Herschel's initials appear in graphite next to the date received. An ink inscription at top of first page reads 'N. T.Y. [Thomas Young]'.
Subject: Geodesy
Written by Macdonald in at Lady Chambers', Richmond [London]. Received by the Royal Society on 19 January 1827 from Davy. |
| Extent | 3p |
| Format | Manuscript |
| Physical description | Ink on paper |
| Access status | Open |
| Related records in the catalogue | AP/12/15 |
Fellows associated with this archive
| Code | Name | Dates |
| NA8200 | Davy; Sir; Humphry (1778 - 1829); chemist | 1778 - 1829 |
| NA3036 | Macdonald; John (1759 - 1831) | 1759 - 1831 |