| RefNo | EL/R1/82 |
| Level | Item |
| Title | Note on a method for determining longitude at sea by two portable pendulum clocks with covering letter by P. I. Rocquette, dated at St Petersbourg [St Petersburg] |
| Creator | Roquette; P. I. (fl. 1732); watchmaker to Anna Ioannovna, Empress of Russia |
| Date | 1732 |
| Description | Date on front cover is 26 October 1732
Covering letter is dated 28 October 1732 |
| Language | English |
| Extent | 17p |
| Format | Manuscript |
| Digital images | View item on Science in the Making |
| AccessStatus | Open |
| RelatedMaterial | Original is EL/R1/79 and EL/R1/81 |
| URLDescription | Also available on Early Modern Letters Online |