Reference numberMS/119/2/90
TitleLetter from John Henry Lefroy, Longwood, St Helena to Humphrey Lloyd, Trinity College, Dublin
Date29 May 1840
DescriptionLefroy discusses setting up a new observatory at Longwood, St Helena. Lefroy notes that the thread has given way which causes the telescope to move and will do until it is let into stone. Lefroy surprised by gradual change in the horizontal force readings, as expected readings to be the opposite from a loss of magnetism, he includes a diagram of his readings from which concludes that the high number indicates increasing force. Lefory sends the new curve and abstract to Lloyd [not enclosed]. Discussion on the dip taken for the present month being affected by weather conditions. Lefroy thanks Lloyd for his paper on three magnets. Discussion on the building, its angle and an extra lens needed for near distances. Lefory apologises for the delay in completion of the new building, but sites there are very few workmen, as all labourers are emigrating from the island to the Cape. Discussion on vertical force needles. Lefroy is looking forward to moving to the observatory and away from temporary arrangements.
Physical descriptionInk on paper
Access statusOpen
Fellows associated with this archive
NA8252Lloyd; Humphrey (1800 - 1881)1800 - 1881
NA7669Lefroy; Sir; John Henry (1817 - 1890)1817 - 1890
Add to My Items

    Collection highlights

    Browse the records of some of our collections, which cover all branches of science and date from the 12th century onwards. These include the published works of Fellows of the Royal Society, personal papers of eminent scientists, letters and manuscripts sent to the Society or presented at meetings, and administrative records documenting the Society's activities since our foundation in 1660.

    The Royal Society

    The Royal Society is a Fellowship of many of
    the world's most eminent scientists and is the
    oldest scientific academy in continuous existence.
    Registered charity number 207043

    Website design ©CalmView


    + 44 207 451 2500
    (Lines open Mon-Fri, 9:00-17:00. Excludes bank holidays)

    6-9 Carlton House Terrace, London SW1Y 5AG

    Email Us →


    Subscribe to our newsletters to be updated with the
    latest news on innovation, events, articles and reports.

    Subscribe →

    © CalmView