George Biddell Airy to Faraday   17 February 1857

1857 Feb 17

My dear Sir

On 1847 May 20 you were so kind as to give me an answer to a question which I had placed before you, relating to the possible preference of a pure metal or an alloy (on the score of durability) for the Standard of Length¹.

Will you permit me to quote your answer, in the Account of Construction of the Standard which I am now drawing up?²

I am, my dear Sir, | Yours very truly, | G.B. Airy

Michael Faraday Esq | &c &c &c