John Tyndall to Faraday   11 July 1852

Queenwood College | near Stockbridge Hants. | 11th, July 1852.

Dear Sir,

I return, with many thanks, the memoir which you were kind enough to lend me¹. I believe I must plead guilty to the charge of keeping it a day beyond the time permitted me, and the reason of my doing so is, that during my stay in London (which I quitted yesterday) I was so tossed about, in mind and body, that the tranquility necessary to the profitable reading of such a paper was denied me. If I dared I would keep it a day or two longer, for a man requires to brood over such a subject, to get as near as possible to the writers point of view, and to familiarize himself with the peculiar form under which the matters treated of present themselves to the writers mind. The constancy of the magnetic force regardless of distance, as indicated by the moving wire, is an exceedingly striking and significant result:--I am still a little in the dark as regards your remark in 3090, that “the system of power about the magnet must not be considered as revolving with the magnet.”² Now in your bar magnets the force emanating from one of the corners is, I imagine, more intense than that emanating from any other point; in the rotation of the magnet this corner moves, and it appears to me that as the line of force emanating from the corner will always preserve the same position with regard to the corner, when the latter revolves the line of force peculiar to it must revolve also. In the case supposed by yourself in 3110³, where the wire and the line of force are conceived to coincide, if the wire and the magnet revolves together I should imagine that the wire and the line of force would continue to coincide, that one would be perfectly motionless with regard to the other, and that hence no current could be formed.

Most heartily do I subscribe to the sentiment expressed in 3159⁴. The object of the analyst in many cases seems to be to draw boundaries and limitations which the advancing experimentalist ever tends to break through. Far be it from me to decry the labours of the analyst - they are the necessary complement to experimental knowledge; but our knowledge is a thing flowing and not a thing fixed, and as long as this is the case the widest generalization which man has yet made is in danger of being swallowed up by one still more comprehensive. The analyst is the exponent of the centripetal tendency of the human mind, while the experimentalist is centrifugal, and seeks continually for still wider expansions.

I am making preparations at present to enter a struggle for a post in one of the Queen’s Colleges in Ireland. The chair of Natural Philosophy in Galway College has become vacant and I intend to become a candidate for the post. Some of my friends have already commenced operations on my behalf - Col Sabine has written to a very influential quarter and other agencies are also at work. The election will probably not be made till towards October; in the mean time I will invoke all the aid I can, and if I fail, the consciousness of having done all it behoved me to do in the matter will be sufficient to render me content.

believe me dear Sir | most faithfully Yours | John Tyndall

Professor Faraday | &c &c &c