Malvernbury House | Malvern, June 1, 1855
My dear Sir
I have asked Mr Weld1 to set aside for you four copies of the joint paper by Mr Joule and myself recently published in the Transactions,2 of which the authors will be gratified by your accepting one. If you will kindly take charge of one for Faraday also, and, in case of Du Bois Reymond being at present lecturing at the Royal Institution, if you will take two copies and give them to him, one for himself and the other for Helmholz,3 I should be much obliged by your taking some opportunity of being at the Royal Society to ask Mr Weld for the four copies which are lying there for you. If you do not chance to be at the Royal Society before the end of the session do not be at the trouble of sending for the papers, as after that time I shall have them all forwarded to myself, and should you not have received a copy I shall have the pleasure of sending you one by post.
Can you tell me whether Helmholz has yet moved to Bonn4 where I understand he is, if not there already, shortly to be settled? I am anxious to know the post office address both for him and Du Bois Reymond, and I should be very much obliged if you could inform me.
I hope you intend to be present yourself at the Glasgow meeting of the British Association5 and to bring any apparatus you may have for illustrating your investigations in magnetism or other branches of experimental science, which may be suitable for bringing before our Section. I shall have much pleasure in hearing from you regarding the instrument of which you promised me a description, or still more in seeing it if you can bring it with you to Glasgow.
I think the phenomena presented by pieces of soft bread containing iron filings or fragments of fine iron wire, regarding which I wrote to you in March,6 must be entirely due to the tendency to form into little rows perpendicular to the line of compression, and to place the lengths of little bars perpendicular to the same line, which such a compound may experience when compressed in one direction.
I am quite out of the world here and have not seen either Philosophical Magazine or Proceedings of the Royal Society for five weeks so that I am in the dark as to recent progress in some of these branches of science to which so much thought is now directed.
Do you know Werner Siemens’ plan for measuring the times occupied by military projectiles in passing over short distances in various parts of their paths?7 I only know it by an allusion to it in the short article on Helmholtz’s observations regarding the velocity of transmission of nervous excitement, wh appeared in the Philosophical Magazine.8 I thought in writing to you to suggest that, if you, or some other competent investigator, could be induced to take it up, it would be an excellent object for an application of part of the Government Grant Fund9 in the present state of national affairs. I see however by a newspaper paragraph that Wheatstone’s plan,10 which he is said to have proposed some years ago, is at last about to be taken up by government, with a view to testing & improving the practice of fire arms. I shd think Wheatstone’s must be something like (whether possessing priority or not) that of Siemens – but I am sure it cannot be better.
Believe me, Dear Sir, Yours very truly | William Thomson
Do you by chance to know in what place (some part of the North of Italy I presume), Maggi,11 (who discovered the unequal thermal conductivity of magnetized iron in different directions) is to be found?
RI MS JT/1/T/13
Mr Weld: see letter 1089, n. 18.
of the joint paper by Mr Joule … Transactions: J. P. Joule and W. Thomson, ‘On the Thermal Effects of Fluids in Motion. Part II’, Phil. Trans., 144 (1854), pp. 321–64. As the Phil. Trans. was an annual publication, these copies would have been pre-prints distributed by the authors.
Helmholz: The eminent German physicist and physiologist Hermann von Helmholtz (1821–94).
whether Helmholz has yet moved to Bonn: In 1855 Helmholtz, who had been lecturing on physiology at the University of Königsberg since 1849, was appointed professor of anatomy and physiology at the University of Bonn. ‘On July 29 [1855], Helmholtz left Königsberg, and went, after a short visit to his relations in Dahlem and Potsdam, to Bonn’ (L. Koenigsberger, trans F. A. Welby, Hermann von Helmholtz (Oxford: Clarendon Press, 1906), p. 144).
at the Glasgow meeting of the British Association: Tyndall did attend the BAAS meeting in Glasgow, 12–19 September 1855 and presented some of his experiments; see later letters.
I wrote to you in March: see letter 1058.
Werner Siemens’ plan … paths: The German industrialist and inventor Werner Siemens (1816–92) devised a method for measuring the speed of projectiles by means of an electric spark: see ‘Ueber die Anwendung des electrischen Funkens zu Geschwindigkeitsmessungen’, Poggend. Annal., 64 (1845), pp. 435–44.
Helmholtz’s observations … Philosophical Magazine: H. von Helmholtz, ‘On the Methods of Measuring Very Small Portions of Time, and their Application to Physiological Purposes’, Phil. Mag., 6 (1853), pp. 313–25. Siemens’ work is discussed on pp. 315–16.
of the Government Grant Fund: In 1849 the British government had instigated an annual grant of £1000 of the Royal Society to aid the promotion of science.
newspaper paragraph … Wheatstone’s plan: ‘“THE TORPID HANDS” OF THE ENGLISH GOVERNMENT. – Some time ago Professor Wheatstone invented an instrument or means, by an electric wire attached to a gun and a target, of measuring with a degree of accuracy never before attained the time occupied in the flight of projectiles. For the improvement of ordnance practice it is acknowledged to be an invention of great value. […] It is now, we are informed, about to be adopted by the Board of Ordnance’ (Dundee Courier, 30 May 1855, p. [2]).
Maggi: Pietro Giuseppe Maggi (1817–73), who may have been a doctor living in Milan, published on a wide range of scientific and non-scientific subjects, including poetry. The paper referred to by Thomson is ‘De l’Influence du Magnétisme sur la Conductibilité pour la Chaleur du Fer Doux’, Bibl. Univ. Archives, 14 (1850), pp. 132–4.
Please cite as “Tyndall1091,” in Ɛpsilon: The John Tyndall Collection accessed on