John Dalton1 to Faraday   20 February 1834

Manchester, Feb. 20th – 1834

Respected Friend

Dr. Faraday,

Mr. Ronchetti2 has just shewn me a very pretty Hydrometer which he is about to send you. He wishes much it may be adopted by the Authorities on the Part of Government. I think a more simple & yet accurate Instrument can scarcely be made. He sells it retail for 50 Shillings & wholesale it would be less. Perhaps if you approve of it you may represent it to the proper quarters. The Glass, Frame &c weighs suppose 6 or 700 parts & weights put on to the scale make up the deficiency to 1000 for water: & whatever weights are added in the scale the aggregate of weights gives the sp. Gr. without any calculation3.

Excuse haste | I remain yours | J. Dalton


Address: Dr. Faraday | Royal Institution | London

1
John Dalton (1766–1844, ODNB). Chemical philosopher who lived in Manchester. Developed a version of the atomic theory of matter.
2
Joshua Ronchetti. Manchester and London scientific instrument maker. See Rea (1988), 5.
3
See Ronchetti to Faraday, 31 March 1835, letter 774, volume 2.

Bibliography

REA, Anthony (1988): Manchester's Little Italy: Memories of the Italian Colony of Ancoats, Manchester.

Please cite as “Faraday0700a,” in Ɛpsilon: The Michael Faraday Collection accessed on 28 April 2024, https://epsilon.ac.uk/view/faraday/letters/Faraday0700a