Marburg 8th March 1851
Dear Sir.
Had I been aware of your inability to find a place for the memoir on magnetism until the April no. of the magazine1 I should have spent more time upon it. – Not that I should have altered any of the facts but I would have modified the arrangement and improved the style. I have made an attempt to accomplish this in some measure with the imperfect means at present within my reach. I have not a copy of the memoir beside me2 but I think my memory will help me to point out clearly the portions which might with benefit be modified –
1. Instead of Proposition 3 as contained in the memoir will you substitute that at α page 1.3 The latter is more definite and reads better.
2. For the paragraph in the memoir which commences with the words ‘Ten years ago Lenz and Jacobi occupied themselves with the solution of the first proposition &c _____ will you be good enough to substitute that at a. page 1.4 You will at once see where the latter runs into the paragraph contained in the memoir – this is an important alteration – if I thought it would interest you I would tell you why – but I spare the space.
3. Instead of the long description of the Taugentenbussole5 and the reference to Bunsens instrument I should feel obliged if you would substitute the two paragraphs which occur between b and b´ –6
4. The definition of the strength of a magnet as contained in the memoir is unnecessarily prolix. Immediately after prop. 1. § 2. the paragraph at bˊ might be introduced7 – This paragraph is sufficient, and will render all that respecting the action of a magnet on a needle placed parallel and perpendicular to the magnetic meridian wholly unnecessary. In fact the development of the formula h = H tang α stands in almost every Lehrbuch8 and is not necessary for the readers of your magazine. In this case also it is easy to see where the alterations must fit in – it will come between the end of prop 1. and the paragraph where Muller’s name is introduced.
5. Immediately after Table I. in the memoir I should feel much obliged if you would introduce the passage at C. page 2.9 The law expressed at the end of table I. will be thus pushed forward to the end of the third table1011 – where it may be expressed as at d. page 3. I have given a sketch of the arrangement as it stands so that I think mistake is hardly possible. The law must stand immediately before the paragraph which contains a description of the method pursued by Lenz and Jacobi with induced currents.12
6. In § 3. occurs the formula
m=f(d)
will you be good enough instead of the arrangement at present existing to adopt that at e. page 3. The law will then come in its proper place, that is after the table instead of before it as at present.13
7. Immediately after the reference to Dubs experiments14 in §. 6. will you be good enough to introduce the remark at F. page 4. and 5. – It may be printed in the form of a note.15
8. In writing the last remark I made a little [spring] – that is to say there is something which requires modification before we reach the allusion to Dub. Immediately after prop 4. §. 6 I have made use of an illustration which perhaps serves rather to confuse the subject in hand than to explain it. You would oblige me if you would omit all that about the melting point of fatty matter16 and introduce simply what stands at G. Page 6.
9. §. 7. commences with the words – ‘Bodies capable of magnetization are divided into two classes &c’ – A little further on the following words occur: ‘At the commencement of this memoir we obtained a notion of the strength of a magnet by its action on a freely suspended magnetic needle.’17 The change made by the paragraph bˊ will render this reference inapplicable for the above words those at H.18 page 7. may be substituted – A little further still it is said ‘Were the case otherwise tang α would not be a correct measure of the magnetic strength’ – These words for the above reason are also inappropriate – thier omission will in no way impair the sense.19
10. At the commencement I believe of (37) occur the words ‘Whence then this singular result’? These words might be left out20 and the words immediately following slightly altered to suit the omission.
11. In (36) I think it is said ‘The following procedure occurred to me on observing the extreme tenuity of a gun cotton balloon’ This remark appears to me to be altogether needless.21
12. The paragraph at the end where reference is made to the number of experiments ought to be entirely omitted – I mentioned this to you before.22
13. In the early part of §. 8. it is said – ‘We have thus arrived by fair deduction from established principles at the celebrated law of Lenz & Jacobi &c’ – will you omit the word ‘celebrated’?23 – not that I wish to detract from the discovers but the word has no business there.
14. Where the former memoirs of Prof. Knoblauch & myself are mentioned – that is where the magnet is described – would you be good enough to refer to the vol and Page of the magazine which contains them.24 and where towards the end of the memoir the pressing together of a plate of glass and a lens of weak curvature is mentioned it would be well to refer to Wildes memoir, a translation of which I sent you last November.25 I have seen the translation but <the> magazine is not now in my possession.26
StBPL T&F, Authors’ letters
aware ... spent more time: in letter 0470 Tyndall had agreed to Francis’s proposal that his memoir on magnetism would be published in the April issue for reasons of balance. His complaint therefore is not simply about the delay. It seems that Francis (in a missing letter) objected to the numerous changes requested by Tyndall, who is here making excuses, without acknowledging that the March publication date was his own wish.
have not a copy ... beside me: although Francis had the only fair copy, Tyndall had made this from a draft (Journal, 23 January 1851, JT/2/13b/520). The level of detail here (including section numbers, proposition numbers and table numbers) suggests that he was relying on his draft and not on his memory.
Proposition 3 ... α page 1: a list of corrections, at least 7 pages long, accompanied this letter and is referred to by page number and paragraph letter (α, a, b, etc). This list is missing. Where the changes can be identified the page number in the published memoir (cited letter 0464, n. 2) is given in the following notes.
at a. page 1: probably the last paragraph on p. 265.
Taugentenbussole: in the published text Tyndall does not use the German term but its English translation, ‘tangent galvanometer’, and variants.
between b and b´: probably the two paragraphs on pp. 267-8 under ‘3’.
after prop. 1 § 2. the paragraph at bˊ might be introduced: this paragraph runs from p. 269 (bottom) to p. 270 (top).
Lehrbuch: textbook.
C. page 2: bottom of p. 271.
[This is] not called Tab. III: if I recollect aright it has not a number
table*: Tyndall’s footnote (above) was located at the bottom of his second sheet.
The law … induced currents: the law is in the second to last paragraph on p. 272.
The law … at present: the law and formula are in the upper half of p. 275.
Dub’s experiments: which measured attraction between a bar and magnets of different thicknesses and at different distances (cited letter 0457, n. 9). Tyndall discussed the experiments in his report on magnetism (cited letter 0459, n. 1).
in the form of a note: note † on p. 284.
the melting point of fatty matter: p. 283.
‘At the commencement … magnetic needle’: this passage remains in the published text (except that ‘obtained a’ is changed to ‘arrived at the’) at p. 287.
H: Tyndall has written this with parallel lines above and below the letter, though it appears simply as ‘H’ in the published translation.
‘Were the case … impair the sense: this passage also remains in the published text (although with ‘strength’ altered to ‘power’) at p. 287. Tyndall mis-spelled ‘their’.
These words might be left out: this was done (p. 292).
This remark … needless: this sentence remains (p. 292).
The paragraph … to you before: Francis let this reference stand (p. 292). The earlier request was probably made in letter 0468, the latter part of which is missing.
fair deduction ... celebrated law: without being so requested by Tyndall, Francis changed ‘fair’ to ‘direct’ and replaced ‘celebrated’ by ‘well known’ (p. 289).
former memoirs ... contain them: see letters 0395, n. 22 and 0403, n. 2.
Wilde’s memoir: a reference is inserted (at p. 293) but without mention of Wilde’s name. For Wilde’s paper see letter 0448, n. 8.
possession.: the extant text ends here. The next fragment, letter 0474, could be a continuation of this letter (see letter 0474, n. 1), but although it is written at almost the same time and requested further changes to the memoir on magnetism, the changes requested do not follow the same numbering system and the manuscript is folded differently. We therefore number them as different letters.
Please cite as “Tyndall0473,” in Ɛpsilon: The John Tyndall Collection accessed on 28 April 2024, https://epsilon.ac.uk/view/tyndall/letters/Tyndall0473