| RefNo | MS/257/5/60 |
| AltRefNo | Sa.1740 |
| Previous numbers | ES5/16/1740 |
| Level | Item |
| Title | Letter from John Welsh, Kew Observatory to Edward Sabine |
| Date | 3 January 1857 |
| Description | Regarding the difference in mean dip at Greenwich for each year compared with ‘interpolated’ dip in Regents Park. Welsh discusses the probability of changes to the instruments being a reason for the ‘discordances’, arguing that ‘some change has been going on’ in the axles. Discussion regarding Greenwich observations for 1851. Reference to [Johann von] Lamont’s work on determining the inclination coefficient. Discussion regarding the magnetic moment and gravity. Welsh would like to ‘call’ on Sabine in order to see Lamont’s drawing of his apparatus and intends to adapt his apparatus accordingly. Mr [Michael] Faraday has received the magnetic apparatus. Welsh informs Sabine they did not get any ‘good’ observations from Mr McLeod’s dip circle. |
| Extent | 7p |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
| RelatedRecord | MS/257/5/61 |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA1680 | Welsh; John (1824 - 1859) | 1824 - 1859 |
| NA8279 | Sabine; Sir; Edward (1788 - 1883) | 1788 - 1883 |