| RefNo | MS/119/2/89 |
| Level | Item |
| Title | Letter from John Henry Lefroy, Longwood, St Helena to Humphrey Lloyd, Trinity College, Dublin |
| Date | 10 April 1840 |
| Description | Lefroy for a delay in sending the magnetic returns for the month. Discussion on the magnetic returns and meteor reports, which have been troublesome because of additional columns to be added and measured. Lefroy discusses the lack of results from the vertical force instrument due to immense rust on the needle, and the position of the centre of gravity. Discussion on measuring the angle of deviation. Lefroy mentions discovering newspaper with a letter titled 'cui bono' on the preparation of the magnets, and discusses using the writers directions. Discussion on Mr [Thomas] Grubb's scales not being perfect. Lefory informs Lloyd that he is sending an account of the experiments made on specimens of the building stone [not enclosed]. Discussion on making observations in connection with Göttingen mean time. Lefroy discusses the results obtained from him experiment on temperature. Lefroy informs Lloyd that the observatory will be roofed by March, and that Captain [James Clark] Ross will most likely be at [Kerguelen Islands] by early May. Discussion on Lefory's telescope and the difficulties he is facing with the transit adjustment. |
| Extent | 5p |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA7669 | Lefroy; Sir; John Henry (1817 - 1890) | 1817 - 1890 |
| NA8252 | Lloyd; Humphrey (1800 - 1881) | 1800 - 1881 |