Reference numberMS/119/2/95
TitleLetter from John Henry Lefroy, Longwood, St Helena to Humphrey Lloyd
Date24 August 1841
DescriptionLefroy is sending comparisons for the month in a supplementary sheet along with extra observations as suggested by Lloyd. Lefroy acknowledges receiving new vertical force needles and dips circle. Based on a recent observation Lefory is convinced that a greater latitude must be granted in this type of station. Lefroy discusses the design of the needle and agates within the dip circle, and its effects, and would like [Thomas Charles] Robinson to furnish the instrument with new needles. Lefroy mentions receiving news from Edward Sabine about his probable transfer to Canada. Stated the course of readjustments of the horizontal force. Is not sure if the torsion microm moved by not being clamped properly or some negligence. Has been looked at every day since. Notes several striking disturbances this month (August) in which the vertical force worked well with the others. Asks Lloyd for explanation of the manner in which the curve of total force can be obtained, and how the corrections for temperature can be applied.
Physical descriptionInk on paper
Access statusOpen
Fellows associated with this archive
NA7669Lefroy; Sir; John Henry (1817 - 1890)1817 - 1890
NA8252Lloyd; Humphrey (1800 - 1881)1800 - 1881
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