R. Institution | 6 May 1847
My dear Airy
Mr. Hall with expressions of much regret denies my request, having certain mechanical improvements which they wish to keep private1.
Ever truly yours | M. Faraday
Please cite as “Faraday1986,” in Ɛpsilon: The Michael Faraday Collection accessed on 28 April 2024, https://epsilon.ac.uk/view/faraday/letters/Faraday1986