Reference numberMS/119/2/70
TitleLetter from Charles James Buchanan Riddell, Maidstone to Humphrey Lloyd
Date12 February 1846
DescriptionRiddell has finished correcting [his instructions], discusses the changes he has made and his travel plans. Discussion on Lloyd’s method for the induction correction. Riddell notes that Lloyd’s method is more likely mathematically correct and convenient, however he is now unable to make any alterations to the formula, as the books have already been printed and circulated. Riddell corrected the angles in order to allow the calculation of the coefficients P and Q, and altered the absolute declination part. Discussion on the induction inclinometer, and separation of permanent and temporary induced magnetism.

Riddell discusses [John Henry] Lefroy’s observations and notes that there are no errors from electricity in the metal rings greater than those attending the determination of inertia with cylinder weights. Riddell has changed the paragraph relating to the differences of absolute values.

Riddell has never used the glass scales and they had been recommended by [Johann von] Lamont.

Riddell has been in Maidstone since the middle of last week after giving over his magnetic duties [at Woolwich]. Riddell plans to go to town next week, then on to Scotland, and then perhaps visiting Canada again to see old friends and the observatory again.

Riddell would like Lloyd to look over papers relating to the mean diurnal variations arranged with a view to probable errors of coefficients.
Physical descriptionInk on paper
Access statusOpen
Fellows associated with this archive
NA7327Riddell; Charles James Buchanan (1817 - 1903)1817 - 1903
NA8252Lloyd; Humphrey (1800 - 1881)1800 - 1881
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