| Reference number | MS/257/5/66 |
| Alternative reference number | Sa.1746 |
| Previous numbers | ES5/16/1746 |
| Level | Item |
| Title | Letter from John Welsh, Kew Observatory to Edward Sabine |
| Date | 24 February 1857 |
| Description | Regarding the negativity and consistency of the changes of vertical force shown by the Toronto balance magnetometer. Discussion regarding the amount of annual decrease shown by the balance magnetometer. Welsh discusses the permanency of the magnetic movement of the vertical force needle, the time of horizontal vibration from 1846 to 1849 and the decrease in magnetic movement. Includes the time of vertical vibration from each year from 1846 to 1848 showing a loss of magnetic movement. Discusses the evidence for the constancy of the magnetic movement during 1841 to 1846. Reference to the secular movements of the vertical force magnet and differential changes.
Dr [William Balfour] Baikie was at the [Kew Observatory] and has ‘taken very readily to the unifilar’. |
| Extent | 11p |
| Format | Manuscript |
| Physical description | Ink on paper |
| Access status | Open |
Fellows associated with this archive
| Code | Name | Dates |
| NA1680 | Welsh; John (1824 - 1859) | 1824 - 1859 |
| NA8279 | Sabine; Sir; Edward (1788 - 1883) | 1788 - 1883 |