John Tyndall to Faraday   26 May 1851

95 Dorothreen-Strasse | Berlin | 26th. May 1851

Dear Sir,

Shall I thank you for your last encouraging letter?¹ By thus doing I should imply that a kind of equilibrium might be established between my thanks and your kindness - this cannot be done and I therefore refrain from making the attempt, appealing rather to my future actions to testify the effect which your inspiring words have had upon me.

I write now just to mention that I had the honour of an interview to-day with Humboldt. I introduced your recent investigations in terrestrial magnetism. “I have read them² with astonishment” was his remark “I do not imagine that very little variation can be thus accounted for but in the main he is correct”[.] His last words to me were - “Tell Mr. Faraday that I am quite convinced of the validity of his hypothesis.”³ Dove⁴ has expressed the same opinion to me.

Could you not pay Berlin a visit? there is no place on earth where you would be more enthusiastically welcomed. Your presence would call forth an exhibition of Hero-worship with which even Thomas Carlyle⁵ himself would be satisfied⁶.

I have been working for the last five weeks at diamagnetism. Prof. Magnus has been kind enough to place the necessary space and apparatus at my disposal - indeed I cannot speak too highly of the kindness of the men of science of Berlin generally.

My results I hope will interest you but I forbear mentioning them as they are not yet complete. It has been again my misfortune to arrive at conclusions very divergent from those of Prof. Plücker. A paper⁷ on the subject shall be ready for the British Association at its next meeting⁸.

Believe me dear Sir, | Most truly and respectfully Yours | John Tyndall

Prof. Faraday | etc. etc. etc.

Since writing the above I have spent a few hours with Du Bois-Raymond and have succeeded completely in developing a current by muscular contracted [sic] - I obtained a deflection of about 30˚ - right or left to the arm contracted. The experiment requires a delicate apparatus and some care. Du Bois’ multiplying Galvanometer contains 24.000 windings[.]