Reference numberMS/119/2/81
TitleLetter from Frederick Marow Eardley-Wilmot, Cape of Good Hope Observatory to Humphrey Lloyd, Trinity College, Dublin
Date5 June 1841
DescriptionEardley-Wilmot mentions the return of the ‘Melville’ to England, ‘after bumping upon the rocks in the China sea’ has allowed him to send his returns for May [not enclosed].

Discussion on the horizontal force instrument and adjusting the scale to focus. This changes the value of the scale and irritates the adjustment of the instrument.

Discussion on observations from the Cape of Good Hope observatory from April and May. Eardley-Wilmot is only sending Lloyd observations from April, as there has been a decrease in the torsion force, they are useless. Eardley-Wilmot notes a decrease in May and some singular movement in all the instruments. Eardley-Wilmot is interested to learn the state of other observatories on 10th and 11th May.

Discussion on dipping needles. Eardley-Wilmot informs Lloyd that he needs a separate place for vibrations. £3000 have already been used in the construction of the Cape of Good Hope observatory, and Eardley-Wilmot does not want to add to this expenditure, therefore he is building at his own expense (£30) a subterranean room 11 feet square. Eardley-Wilmot requests Lloyd to ask [Thomas] Grubb to send him magnetical instruments.

Eardley-Wilmot is puzzled by the inconsistent movements of the vertical force instrument. Discussion on [John Henry] Lefroy’s letters to Eardley-Wilmot regarding this. Discussion on the difficulties with the vertical force instrument, and how to move the needle at each observation.

Eardley-Wilmot installed an additional door into the observing room and notes the effects this has on the temperature.

Completion of another set of temperature experiments by heating the dip house during experiments of vibration.

Discussion on the chronometer.

Eardley-Wilmot mentions buying a large cedar barrel seven feet high and four feet in diameter from a ‘condemned slaver’ [referring to a slaving ship].

Eardley-Wilmot discusses the necessity of measuring the absolute intensity every month, as opposed to every two months.
Physical descriptionInk on paper
Access statusOpen
Fellows associated with this archive
NA6061Eardley-Wilmot; Frederick Marow (1812 - 1877)1812 - 1877
NA8252Lloyd; Humphrey (1800 - 1881)1800 - 1881
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