| Reference number | LBO/25/70 |
| Alternative reference number | LBO/25/278 |
| Level | File |
| Title | Copy letter from John Martyn, Chelsea, to John Machin |
| Date | 21 April 1739 |
| Description | ' A Letter from Mr Professor MArtyn to Mr Machin, containing his Observations of an uncommon Aurora borealis on 20 April 1739. '
Read to the Royal Society on 10 May 1739 |
| Extent | 2p |
| Format | Manuscript |
| Access status | Open |