| RefNo | MS/119/2/12 |
| Level | Item |
| Title | Incomplete letter from Charles James Buchanan, Toronto to Humphrey Lloyd, Trinity College, Dublin |
| Date | 26 May 1840 |
| Description | Riddell updates on the building works for the Toronto observatory, and work that has been completed so far. Riddell thanks Lloyd for his letter and a paper on the mutual action of magnets. Riddell notes the delays and uncertainty of the Halifax government mails. Riddell hopes to receive the register next month. Riddell comments on Lloyd’s paper on the mutual action of magnets in which Lloyd suggests placing the magnets in a right line. Discussion on the force created by magnets being in complete equilibrium, and movements of absolute intensity.
Discussion on replacing the horizontal force and vertical force magnets. Riddell adjusted the horizontal force to get the line of meridian accurately and made several observations with the bar direct and reversed, noting that drawing it out of the bar and replacing it in the same position caused a change. The azimuth remained unchanged. Riddell ascribes this to the stirrup being too large for the bar.
Riddell discusses Lloyd’s approval for wood being used in the building of the observatory. Discussion on the building at the works underway. Riddell expects to be ready with the instruments by the July term day.
Riddell had another trial with the vertical force magnetometer. Discussion on the placement of the instruments, and their distances from each other. |
| Extent | 4p |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA7327 | Riddell; Charles James Buchanan (1817 - 1903) | 1817 - 1903 |
| NA8252 | Lloyd; Humphrey (1800 - 1881) | 1800 - 1881 |