To George Gabriel Stokes

My dear Mr. Stokes

I waited till I sh^d be able to write to you a letter fully regarding my paper.¹ The aqueous vapour question has become of such interest that I think I must ask you to publish a drawing of the apparatus² with which I proved its action where the rock salt plates were absent. I shall call upon my draughtsman today & if possible get the drawing from him. I think I will omit the others thro’ sheer want of time to draw them. The letter press may be allowed a little accordingly.

It is not at all uncommon to use the thermo electric pile with a coating of soot exactly such as Melloni & Magnus used on the plates of rock salt. I have the very highest admiration for Melloni’s ingeniousness as an experimenter & for his clearness as a reasoner; but he is not without his error & failings. He has made, as all men who work so long as he did will do—several mistakes; and this lampblack affair³ is one of them. Of course all that I have stated is perfectly correct, but I am quite willing to publish anything you might suggest to take the edge off my remarks though I had no intention of furnishing them with an edge at all.

I should be very glad if anything struck you in my remarks regarding Magnus⁴ that might be softened or improved if you would inform me. I do not wish to say a word which could unnecessarily hurt him.

Yours very since[re]ly | John Tyndall

Tomorrow evening I quit London & will be absent for 8 or 10 days.⁵

Stokes Correspondence, Cambridge University Library/MS.Add.7656/T553,1(4)-4(4)