| RefNo | MS/119/2/101 |
| Level | Item |
| Title | Letter from John Henry Lefroy, Toronto to Humphrey Lloyd |
| Date | 28 April 1848 |
| Description | Lefroy discusses his decision to not complete the examination of the bifilar coefficient by Mr Brown. Discussion on Lefroy deducing a satisfactory value for the coefficients of both bifilars from a comparison with observed vibrations from another magnet. Lefroy includes a value for K concluded from groups each containing 50 equations using results from 1846 and 1847, and discusses his findings. Comparison between the small and large bifilar on the change of force, Lefroy and asks Lloyd his opinion on this significant difference. Discussion on Lefroy's Athabasca, Canada observations, and comparison between Athabasca and Toronto's mean disturbance of declination. Discussion on magnetical influences and the diurnal change. Lefroy asks Lloyd the possibility of a high tide of magnetical influences which differ from those produced by regular diurnal changes, and that it is progressive across the globe and has a different hour in different region. Discussion on monthly mean irregular fluctuations at Athabasca and Toronto stations. |
| Extent | 8p |
| 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 |