| RefNo | MS/119/2/139 |
| Level | Item |
| Title | Copy of a letter from Humphrey Lloyd, Trinity College, Dublin to John Allan Broun |
| Date | 15 April 1843 |
| Description | Lloyd recommends to Broun not to print his results until temperature and mean value corrections have been made. Lloyd notes that corrections can be obtained if care is taken in the experiment of deflection. Lloyd discusses Broun's method of comparing results at different temperatures and its effects. Lloyd comments on Broun's vertical force needle, the changes in its time of vibration being extremely satisfactory, whereas the effect of temperature is greater than expected. Lloyd advises that the effect of temperature on the vertical force magnet should be submitted to calculation. Discussion on the construction of the vertical force bar. Lloyd discusses Broun's results for the correcting thermometers.
Discussion on the differences between the thermometer and magnets, Lloyd procured a thermometer from [John Newman] with a brass bar of the same size and shape as the horizontal force magnet and this seems to solve the problem. Lloyd notes he has written a paper outlining this method in the revised instructions. But was encouraged by Mr [George Biddell] Airey to omit this, as he was not completely satisfied with the view Lloyd had adopted.
Lloyd suggests projecting in curves the diurnal changes of all the magnetic and meteorological elements. |
| Extent | 2p |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA8252 | Lloyd; Humphrey (1800 - 1881) | 1800 - 1881 |
| NA3813 | Broun; John Allan (1817 - 1879) | 1817 - 1879 |