George Biddell Airy to Faraday   14 November 1855

Royal Observatory Greenwich | 1855 Novr. 14

My dear Sir

Will you let me ask you instruction on a chemical matter.

We have photographic registers of the movements of our magnets, of which I desire to multiply copies. This we can do photographically, but the expence is alarming. In the largest number, I do not think that we can make them for less than 6d a leaf, small in itself, but large when multiplied annually by 22000.

Now would it be possible for the action of sun-light through our primaries or secondaries to produce an action on the surface of any metal plates &c which would make them competent to print like zincographs?

Or can you suggest any other and wholesale way of producing say 30 copies of every photographic sheet?

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

Professor Faraday | &c &c &c