| RefNo | MS/119/2/90 |
| Level | Item |
| Title | Letter from John Henry Lefroy, Longwood, St Helena to Humphrey Lloyd, Trinity College, Dublin |
| Date | 29 May 1840 |
| Description | Lefroy discusses setting up a new observatory at Longwood, St Helena. Lefroy notes that the thread has given way which causes the telescope to move and will do until it is let into stone. Lefroy surprised by gradual change in the horizontal force readings, as expected readings to be the opposite from a loss of magnetism, he includes a diagram of his readings from which concludes that the high number indicates increasing force. Lefory sends the new curve and abstract to Lloyd [not enclosed]. Discussion on the dip taken for the present month being affected by weather conditions. Lefroy thanks Lloyd for his paper on three magnets. Discussion on the building, its angle and an extra lens needed for near distances. Lefory apologises for the delay in completion of the new building, but sites there are very few workmen, as all labourers are emigrating from the island to the Cape. Discussion on vertical force needles. Lefroy is looking forward to moving to the observatory and away from temporary arrangements. |
| Extent | 4p |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA8252 | Lloyd; Humphrey (1800 - 1881) | 1800 - 1881 |
| NA7669 | Lefroy; Sir; John Henry (1817 - 1890) | 1817 - 1890 |