To George Gabriel Stokes   15th March 1862

15^th March 1862

My dear Mr. Stokes,

I have read Mr. Walker’s¹ paper, and though I cannot say that I have mastered its more minute details, which would be difficult without seeing the observations actually performed, I have been sufficiently informed by my perusal of it to enable me to recommend its publication in the Philosophical Transactions.² I think the assiduity Mr. Walker has displayed in collecting his results worthy of the especial encouragement of the Royal Society;

The question as it stands is just in that position which excites a desire to know more about it. The operator must have the means of varying the conditions of his experiments, and must not be confined to telegraph lines. Preliminary experiments would doubtless indicate the best mode of creating a permanent apparatus for the systematic observation of the currents. Probably such experiments would involve but little outlay. This I think certain that a working apparatus many thousand times more delicate than that employed by Mr. Walker might be devised, and with such an apparatus the deflections which he has observed might be obtained with an infinitesimal fraction of the amount of wire which he uses.

At all events, I should hardly think of erecting a permanent or expensive apparatus without ascertaining beforehand the real necessities of the case. I should not be surprised if a single paddock, or even a good sized yard were found sufficient for the collection of the desired currents; and if it is proved to be the case the advantage of being able to change the conditions of experiments promptly would be immense.

Yours very truly | John Tyndall

RS RR/4/277