Marburg 10th August 1852
My dear friend,
I but now write to you to answer and send you my best thanks for your kind letter of the 5th of July.1 But it is not now that I have performed your commissions2 at least as far as I could do with them. A short time after the arrival of your letter I wrote to Kleiner3 in Berlin to order the Thermosaule.4 I have instructed him to give it the same size and arrangement with my own instrument, which I have found satisfactory in all my inquiries since a great number of years. As I had bespoken the matter with Mr Hirst I ordered him to send the apparatus to Marburg directly or in the course of August, as I am here during this time. Or if it were impossible to get the instrument ready in this time, keep it in Berlin until Mr Hirst comes to fetch it. As for the krystals, I have written to Albert5 in Frankfurt on the Main the same from whom I get all my krystals myself as you are aware of. He at least is the best I know though I have not always been satisfied by his cutting of the crystals. Certainly he will send a number of cubes. Among them one or the other will do for the purpose. It was the same in my last inquiries and I confess that without Albert I indeed have not been able to perform the best part of them.
Kleiner has given me no answer. Albert writes that it will be impossible to get Agate (white or yellow) clear. It is always unhomogeneous and only imperfectly transparent so that it will scarcely possible to determine the optic axes. [Dichroite6] also is never perfectly translucid. The size will be 3/10 inch as near as possible but not exactly so in every case, some crystals will be smaller.
You wish to have some convenient means to fix the crystals in order to pass the heat through them. I have now ordered something of this kind with a mechanist to spare you the expense for it. I fixed the crystal in my own experiments on a square piece of wood, which I had prepared myself, able to be turned round its vertical axis for 90 degrees.
Of course I have hastened your commissions as much as possible but my own experience with German mechanics gives me no particular trust in their functionality. I [must] wait about half a year for my thermo-pile, and some crystals, which I had ordered in october last, didnot arrive here before July. – However I shall do what is in my power: I shall write from time to time to Berlin and Frankfurt and treat your affair like my own.
Mrs K. and my father return their best compliments to you. I am very happy to have established my home in my house and wish that you might soon follow my example.
I was in this semester very near to leave Marburg as I had got a vocation to Halle. But when the Cassel government had offered to me the ordinary professorship with more than the double of my former income, I followed my inclination to stay further in Marburg a town which I like very much, as well as Mrs K. who has made some parties in our beautiful neighbourhood. By my new situation I have become a member of the Examinators and Mr Gerland, whom you no doubt remember, was the first who was examined by me in Physics.
Prof. Bunsen leaves Breslau in this vacation-time to go to Heidelberg where he has accepted a professorship7 and the directory of the chemical laboratory.
I address you my best thanks, my dear friend, for the great pains you have undergone in translating my paper on the transmission of radiant heat through crystals.8 You are indeed very kind! Believe me that I feel thankful to you. With great pleasure I remember the time you were working in my rooms and I sincerely wish that a similar time may come again.
Your communication about Mr Powell’s lecture on my experiments9 was the first I heard of it. Where is the whole lecture printed?
I have been glad hearing your election as a member of the Royal Society and congratulate you with all my heart.
I expect my father this evening in Marburg. He comes from Reinerz,10 a bathing place in Silesia. I am just going to the station to receive him.
With my best wishes for you, believe me most sincerely | ever yours | Herm. Knoblauch.
For the relation between the deviation of the needle (and the force) in the thermomultiplier look:
Becquerel. Traite de l’électricité IV, 3, 5.11 – Ann. de Chim. et de Phys. XXXI, 371.12 Pogg. Ann. IX, 345;13 LVI, 325.14
Pogg. XVII, 54315
Nobili Ann. de Chim. et de Phys. XLIII, 146.16 Pogg. Ann. XX, 226 sqq. 232 sqq.17 LVI, 32518 –
Maced. Melloni Biblioth. univ. LV, 19 sqq.19 Mém. de l’Acad. XIV 445 sqq. (ref. Biot).20 An. de Chim. et de Phys. LIII, [5] sqq21 LV, 337 sqq.22 Pogg. An. XXXV, 128-134,23 395 sqq.24 XXXVIII, 11 sqq. 14, 23.25 XXXIX, 7, 8,26 LVI, 326.27
Mém. de L’Acad. XIII.28 – An. de Chim. et Phys. LXXXV, 337 sqq.29 L’Institut 89 p. 22.30 Pogg. An. LII, 574, 57531
Petrina, v. Holgers Zeitschrift fur Phys. I, 171.32 Pogg. An LVI, 328.33
Poggendorff. Pogg. An. LVI, 324, 329 sqq.34
Melloni has found for his instrument the following table: | (Pogg. XXXV p. 133).35
| deviations | forces | deviations | Forces | deviations | forces |
| 20° | 20,0 | 31 | 37,4 | 41 | 65,5 |
| 21 | 21,1 | 32 | 39,6 | 42 | 69,3 |
| 22 | 22,3 | 33 | 41,8 | 43 | 73,2 |
| 23 | 23,7 | 34 | 44,1 | 44 | 78,0 |
| 24 | 25,1 | 35 | 46,7 | 45 | 83,2 |
| 25 | 26,6 | 36 | 49,5 | ||
| 26 | 28,2 | 37 | 52,4 | ||
| 27 | 29,9 | 38 | 55,4 | ||
| 28 | 31,6 | 39 | 58,5 | ||
| 29 | 33,4 | 40 | 61,9 | ||
| 30 | 35,3 |
Farewell! | yours | most truly | H.K.
RI MS JT/1/K/18
letter of the 5th of July: letter missing. Tyndall referred to this letter when he wrote to Hirst (letter 0638).
your commissions: Tyndall asked Knoblauch for a thermosäule and a number of cube of crystals. See letter 0638. Knoblauch’s English was not always perfect.
Kleiner: or Kleimer; an instrument-maker or dealer.
Thermosaule: see letter 0638, n. 9.
Albert: J. W. Albert, a mineral dealer.
Dichroite: alternate name for iolite, a blue crystal, though commonly showing various colours when viewed from different angles.
accepted a professorship: Bunsen succeeded Leopold Gmelin at the University of Heidelberg in 1852.
translating my paper… crystals: H. Knoblauch, ‘On the Dependence of Radiant Heat in its passage through Crystals upon the direction of transmission’, in J. Tyndall and W. Francis (eds.), Scientific Memoirs (London: Taylor and Francis, 1853), pp. 99–113. Originally published as H. Knoblauch, ‘Ueber die Abhängigkeit des Durchgangs der Wärme durch Krystalle von ihrer Richtung in denselben’, Poggend. Annal. 85:2 (1852), pp. 169–88.
Mr. Powell’s lecture on my experiments: Baden Powell lectured on Knoblauch’s work in his ‘On the Analogies of Light and Heat’ at the RI on Friday, 23 April 1852.
Reinerz: a spa town in the Klodzko Valley on the Bystrzyca River in lower Silesian Voivodeship, Poland where there were iron springs.
Traite de l’électricité IV, 3, 5: A. C. Becquerel, Traité d’électricité et du magnétisme, 7 vols (1834–40).
Ann. de Chim. et de Phys. XXXI, 371: A. C. Becquerel, ‘Recherches sur les effets électriques de contact produits dans les changements de temperature et application qu’on peut en faire à la determination des hautes températures’, Annal. Chim. et Phys., 31 (1826), pp. 37–92.
Pogg. Ann. IX, 345: A. C. Becquerel, ‘Untersuchung über die durch Temperaturdifferenzen erzeugte Contactelektricität und deren Anwendung zur Bestimmung hoher Temperaturen’, Poggend. Annal., 9:2 (1827), pp. 345–59.
LVI, 325: J. C. Poggendorrf, ‘Von dem Gebrauch der Galvanometer als Messwerkzeuge’, Poggend. Annal., 56:6 (1842), pp. 324–44.
Pogg. XVII, 543: A. C. Becquerel, ‘Vom thermo-elektrischen Vermögen der Metalle’, Poggend. Annal., 17:12 (1829), pp. 535–54. This was written in the left margin.
Ann. de Chim. et de Phys. XLIII, 146: L. Nobili, ‘Sur la mesure des conrants électriques ou projet d’un galvanometer comparable’, Annal. Chim. et Phys., 43 (1830), pp. 146–87.
Pogg. Ann. XX, 226 sqq. 232 sqq: L. Nobili, ‘Ueber die Messung elektrischer Ströme, oder Vorschlag zu einem vergleichbaren Galvanometer’, Poggend. Annal., 20:10 (1830), pp. 213–245.
LVI, 325: see n. 14.
Biblioth. univ. LV, 19 sqq: Knoblauch may have meant M. Melloni, ‘Appréciation exacte de l’intensité des courants électriques, au moyen du galvanomètre’, Archives des sciences physiques et naturelles á la Bibliothéque Universelle, Genéve, 55 (1834), pp. 9–15.
(ref. Biot): J. B. Biot, ‘Rapport fait à l’Académie des Sciences sur les experiences de M. Melloni relatives à la chaleur rayonnante’, Comptes rendus hebdomadaires des séances de l'Académie des Sciences, 14 (1838), pp. 433–572.
An. de Chim. et de Phys. LIII, [5] sqq: M. Melloni, ‘Mémoire sur la transmission libre de la chaleur rayonnante par différents corps solides et liquides’, Annal. Chim. et Phys., 53 (1833), pp. 5–73.
LV, 337 sqq: M. Melloni, ‘Nouvelles recherches sur la transmission immediate de la chaleur rayonnante par différents corps solides et liquides’, Annal. Chim. et Phys., 55 (1833), pp. 337–97.
Pogg. An. XXXV, 128-134: M. Melloni, ‘Ueber den freien Durchgang der strahlenden Wärme durch verschiedene starre und flüssige Körper’, Poggend. Annal., 35:5 (1835), pp. 112–39.
395 sqq: M. Melloni, ‘Neue Untersuchungen über den unmittelbaren Durchgang der strahlenden Wärme durch verschiedene starre und flüssige Körper’, Poggend. Annal., 35:5 (1835), pp. 385–413.
XXXVIII, 11 sqq. 14, 23: J. B. Biot, ‘Bericht an die Academie der Wissenschaften zu Paris über Hrn. Melloni's Versuche in Betreff der strahlenden Wärme’, Poggend. Annal., 38:5 (1838), pp. 1–50.
XXXIX, 7, 8: M. Melloni, ‘Ueber die Polarisation der Wärme’, Poggend. Annal., 39:9 (1838), pp. 1–32.
LVI, 326: see n. 14.
Mém. de L’Acad. XIII: not identified.
Annal. de Chim. et Phys. LXXXV, 337 sqq: Knoblauch may have meant M. Melloni, ‘Mémoire sur la constance de l’absorption calorifique exercée par le noir de fumée et par les métaux’, Annal. Chim. et Phys., 75 (1840), pp. 337–88.
L’Institut 89 p. 22: not identified.
Pogg. An. LII, 574, 575: M. Melloni: ‘Ueber die Beständigkeit der Wärme-Absorption des Kienrusses und der Metalle, und über das Daseyn eines Diffusionsvermögens, welches durch seine Veränderungen den Werth des Absorptionsvermögens bei den übrigen Körpern verändert’, Poggend. Annal., 52:4 (1841), pp. 573–85. This was written in the left margin.
Holgers Zeitschrift fur Phys. I, 171: F. A. Petrina, ‘Beiträge zur Kenntniss elektischer Ströme’, Wiener Zeitschrift für Physik, Chemie und Mineralogie, 1:3 (1840), pp. 165–80.
Pogg. An LVI, 328: see n. 14.
Pogg. An. LVI, 324, 329 sqq: see n. 14.
(Pogg. XXXV p. 133): see n. 23.
Please cite as “Tyndall0651,” in Ɛpsilon: The John Tyndall Collection accessed on 27 April 2024, https://epsilon.ac.uk/view/tyndall/letters/Tyndall0651