| RefNo | MS/119/1/124 |
| Level | Item |
| Title | Letter from Humphrey Lloyd, Trinity College, Dublin to Edward Sabine |
| Date | 27 December 1847 |
| Description | Discussion on the induction inclinometer and its function for observation of disturbances near the pole. Lloyd advises Sabine to use the bifilar magnetometer and the accuracy in the changes of the dip. Lloyd gives Sabine the formula of the temperature correction of the induction inclinometer. Discussion on obtaining the coefficient for the separate bars, using water of different temperatures, and observing the corresponding changes of angle. Lloyd notes the formula if the effects of heat on the two bars is obtained separately. Equation for the constant coefficient. Lloyd argues that the induction magnetometer will be ‘infinitely preferable’ in comparison to the balance magnetometer.
Lloyd discusses adjustments to his own instrument. Lloyd was dissatisfied with the brass circle which [Henry] Barrow had provided, however as Barrow had rejected Lloyd’s proposed adjustments, Barrow was allowed to make the adjustments he wished. However, Lloyd worked on Barrow’s method, and decided to discard, and to make the adjustments with the magnetic needle. Lloyd has written a memorandum of his mode of adjustments.
Lloyd hopes [James Clark] Ross’s observers are able to make deflection observations in order to get the values of p and q. Lloyd advises shorter deflection distances. |
| Extent | 10p |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA8279 | Sabine; Sir; Edward (1788 - 1883) | 1788 - 1883 |
| NA8252 | Lloyd; Humphrey (1800 - 1881) | 1800 - 1881 |