Published online by Cambridge University Press: 07 November 2013
In the early nineteenth century, Norwegian mathematician and astronomer Christopher Hansteen (1784–1873) contributed significantly to international collaboration in the study of terrestrial magnetism. In particular, Hansteen was influential in the origin and orientation of the magnetic lobby in Britain, a campaign which resulted in a global network of fixed geomagnetic observatories. In retrospect, however, his contribution was diminished, because his four-pole theory in Untersuchungen der Magnetismus der Erde (1819) was ultimately refuted by Carl Friedrich Gauss in Allgemeine Theorie des Erdmagnetismus (1839). Yet Hansteen's main contribution was practical rather than theoretical. His major impact was related to the circulation of his instruments and techniques. From the mid-1820s, ‘Hansteen's magnetometer’ was distributed all over the British Isles and throughout the international scientific community devoted to studying terrestrial magnetism. Thus in the decades before the magnetic crusade, Hansteen had established an international system of observation, standardization and representation based on measurements with his small and portable magnetometers.
1 Pedersen, Kurt Möller, ‘Hansteen, Christopher’, in Gillispie, Charles Coulston (ed.), Dictionary of Scientific Biography, vol. 6, New York: Charles Scribner's Sons, 1972, pp. 106–107Google Scholar; Enebakk, Vidar and Pettersen, Björn Ragnvald, ‘Christopher Hansteen and the Observatory in Christiania’, in Wolfschmidt, Gudrun (ed.), Cultural Heritage of Astronomical Observatories: From Classical Astronomy to Modern Astrophysics, Berlin: Bäßler-Verlag, 2009, pp. 260–273Google Scholar.
2 Aubin, David, Bigg, Charlotte and Sibum, H. Otto (eds.), The Heavens on Earth: Observatories and Astronomy in Nineteenth-Century Science and Culture, Durham, NC: Duke University Press, 2010Google Scholar.
3 Hansteen, Christopher, Untersuchungen über den Magnetismus der Erde, Erster Teil. Die mechanischen Erscheinungen des Magneten (tr. Peter Treschow Hanson), Christiania: Jacob Lehmann und Chr. Gröndahl, 1819Google Scholar.
4 Hansteen, op. cit. (3), pp. 199, 225, 242. See Horn, Werner, ‘Die geschichte der Isarithmenkarten’, in Neef, Ernst (ed.), Petermanns Geographische Mitteilungen, Gotha: Hermann Haack, 1959, pp. 225–232Google Scholar.
5 Hansteen, Christopher, Reise-Erinnerungen aus Sibirien, Leipzig: Verlagsbuchhandlung von Carl B. Lorch, 1854Google Scholar; Hansteen, Christopher and Due, Christian, Resultate magnetischer, astronomischer und meteorologischer Beobachtungen auf einer Reise nach dem östlichen Sibirien in den Jahren 1828–1830, Christiania: Brögger & Christie, 1863Google Scholar; Gauss, Carl Friedrich, ‘Allgemeine Theorie des Erdmagnetismus’, in Gauss, Carl Friedrich and Weber, Wilhelm, Beobachtungen des magnetischen Vereins im Jahre 1838, Leipzig: Verlage der Weidmannschen Buchhandlung, 1839, pp. 1–57Google Scholar. Quote from Pedersen, op. cit. (1), p. 107.
6 Cawood, John, ‘The Magnetic Crusade: science and politics in early Victorian Britain’, Isis (1979) 70, pp. 493–518Google Scholar, 506. See also Morrell, Jack and Thackray, Arnold, Gentlemen of Science: Early Years of the British Association for the Advancement of Science, Oxford: Clarendon Press, 1981, pp. 353–370Google Scholar, 523–529.
7 Cawood, op. cit. (6), p. 578; Morrell and Thackray, op. cit. (6), pp. 524–525.
8 Hansteen, Christopher, ‘Lettre de M. Hansten à M. Örsted’, Journal de physique, de chimie et d'histoire naturelle et des arts (1812) 75, pp. 418–429Google Scholar; Hansteen, , ‘Ueber die vier magnetischen Pole der Erde, Perioden ihrer Bewegung, Magnetismus der Himmelskörper und Nordlichter’, Journal für Chemie und Physik (1813) 7, pp. 79–91Google Scholar.
9 Christopher Hansteen to Hans Christian Örsted, 14 December 1821, in Correspondence de H.C. Örsted, ed. Marius Christian Harding, 2 vols., Copenhagen: H. Aschehoug & Co, 1920, vol. 1, pp. 121–122.
10 Jens Jacob Keyser to Christopher Hansteen, 1 November 1819, Hansteen Papers, Institute for Theoretical Astrophysics, University of Oslo (subsequently UO).
11 Thomson, Thomas, Travels in Sweden, during the Autumn of 1812, London: Robert Baldwin, 1813Google Scholar; Thomson, , ‘Magnetism’, Annals of Philosophy (1818) 12, pp. 389–390Google Scholar; Thomson, , ‘Untersuchungen uber den Magnetismus der Erde’, Annals of Philosophy, new series (1821) 1, pp. 138–140Google Scholar.
12 Stamp, Tom and Stamp, Cordelia, William Scoresby: Arctic Scientist, Whitby: Caedmon of Whitby Press, 1975, p. 64Google Scholar; McConnell, Anita, ‘The scientific life of William Scoresby Jnr, with a catalogue of his instruments and apparatus in the Whitby Museum’, Annals of Science (1986) 43, pp. 257–286Google Scholar; Bravo, Michael Trevor, ‘Geography of exploration and improvement: William Scoresby and Arctic whaling, 1782–1822’, Journal of Historical Geography (2006) 32, pp. 512–538Google Scholar.
13 Michael Trevor Bravo, ‘Science and discovery in the Admiralty voyages to the Arctic regions in search of a north-west passage (1815–25)’, PhD thesis, University of Cambridge, 1992, pp. 48–49; Levere, Trevor Harvey, Science and the Canadian Arctic: A Century of Exploration, 1818–1918, Cambridge: Cambridge University Press, 1993Google Scholar; Fulford, Tim, Lee, Debbie and Kitson, Peter J., Literature, Science and Exploration in the Romantic Era: Bodies of Knowledge, Cambridge: Cambridge University Press, 2004, pp. 149–175Google Scholar.
14 Morrell and Thackray, op. cit. (6), p. 354.
15 Miller, David Philip, ‘The revival of the physical sciences in Britain, 1815–1840’, Osiris, 2nd series (1986) 2, pp. 107–134CrossRefGoogle Scholar, 118.
16 Bravo, op. cit. (13), p. 52, also p. 122.
17 Hansteen, op. cit. (3), p. xxvi.
18 Joseph Banks to Christopher Hansteen, 14 September 1819, UO.
19 Enebakk, Vidar and Johansen, Nils Voje, Christopher Hansteens ‘annus mirabilis’. Reisen til London og Paris 1819, Oslo: Forum for University History, University of Oslo, 2011Google Scholar.
20 Christopher Hansteen to Charles Babbage, 21 April 1857, Papers of Charles Babbage, 1791–1971, British Library, London; Christopher Hansteen to Michael Faraday, 30 December 1857, in The Correspondence of Michael Faraday, ed. Frank James, 6 vols., London: The Institution of Engineering and Technology, 1991–2008, vol. 5, pp. 322–324.
21 Hansteen, Christopher, ‘Om Antallet og Beliggenheden af Jordens magnetiske Poler’, Magazin for Naturvidenskaberne (1823) 1, pp. 1–46Google Scholar, 18–19.
22 John Barrow to Thomas Young, 14 April 1827, Papers of the Royal Greenwich Observatory, Cambridge University Library, RGO 14/44/48.
23 Morrison-Low, Alison and Christie, John C.C. (eds.), Martyr of science: Sir David Brewster 1781–1868:Proceedings of a Bicentenary Symposium Held at the Royal Scottish Museum on 21 November 1981, Edinburgh: Royal Scottish Museum, 1984Google Scholar.
24 Thomas Carlyle to David Brewster, 18 May 1820, in The Collected Letters of Thomas and Jane Welsh Carlyle (ed. Charles Richard Sanders et al.), 38 vols. (ongoing), Durham, NC: Duke University Press, 1977–2011, vol. 7, pp. 368–369; Carlyle, Thomas, ‘Remarks upon Professor Hansteen's inquiries concerning the magnetism of the Earth’, Edinburgh Philosophical Journal (1820) 3, pp. 124–138Google Scholar; Carlyle, , ‘Remarks upon Professor Hansteen's inquiries concerning the magnetism of the Earth’, Edinburgh Philosophical Journal (1821) 4, pp. 114–124Google Scholar.
25 Brewster, David, ‘Account of the expedition to Baffin's Bay, under Captain Ross and Lieutenant Parry’, Edinburgh Philosophical Journal (1819) 1, pp. 150–159Google Scholar; Brewster, , ‘Notice respecting Hansteen's chart of the variations and the dip of the needle’, Edinburgh Philosophical Journal (1821) 4, pp. 363–364Google Scholar, Plate IV; Hansteen, op. cit. (21).
26 Cavendish, Henry, ‘An account of the meteorological instruments used at the Royal Society's house’, Philosophical Transactions of the Royal Society of London (1776), 66, pp. 375–401Google Scholar.
27 As of today, only four exemplars of Hansteen's magnetometer are known to the author; one at the Norwegian Museum of Science and Technology, Oslo; one at the Institute of Astrophysics, University of Oslo; and two at Tromsø Geophysical Observatory, University of Tromsø.
28 McConnell, Anita, Geomagnetic Instruments before 1900, London: Harriet Wynter Ltd, 1980, p. 28Google Scholar.
29 Multhauf, Robert and Good, Gregory, A Brief History of Geomagnetism and a Catalogue of the Collections of the National Museum of American History, Washington, DC: Smithsonian Institution Press, 1987, p. 15Google Scholar.
30 Good, Gregory, ‘Magnetometer’, in Bud, Robert and Warner, Deborah Jean (eds.), Instruments of Science: An Historical Encyclopedia, New York and London: Garland Publishing Inc., 1998, pp. 368–371Google Scholar, 369.
31 Wleugel, Peter Johan, ‘Formodning om at Magnetnaalen her i Kiöbenhavn har naaet sit Maximum af vestlig Afvigning’, in Det Kongelige Danske Videnskabernes Selskabs physiske Skrifter, Copenhagen: Kgl. Danske Videnskabernes Selskab, 1821, pp. 97–120Google Scholar; Peter Johan Wleugel to Christopher Hansteen, 1717–1919, UO.
32 Hansteen, Christopher, ‘Magnetiske Intensitets-Iagttagelser, anstillede paa forskjellige Reiser i den nordlige Deel af Europa, I’, Magazin for Naturvidenskaberne (1824) 4, pp. 269–316Google Scholar, 276.
33 Christopher Hansteen to Hans Christian Örsted, 30 June 1834, in Correspondence de H.C. Örsted, op. cit. (9), p. 164.
34 Hansteen, op. cit. (32); Hansteen, Christopher, ‘Beobachtungen über die Intensität des Magnetismus im nördlichen Europa, I’, Annalen der Physik und Chemie (1825) 79, pp. 225–270Google Scholar, 353–428.
35 Christensen, Dan Ch., Naturens tankelæser: En biografi om Hans Christian Örsted, 2 vols., Copenhagen: Museum Tusculanums Forlag, 2009, vol. 2, pp. 646–707Google Scholar.
36 Hansteen, Christopher, ‘Magnetiske Intensitets-Iagttagelser, anstillede paa forskjellige Reiser i den nordlige Deel af Europa, II’, Magazin for Naturvidenskaberne (1825) 5, pp. 1–74Google Scholar; Hansteen, , ‘Beobachtungen über die Intensität des Magnetismus im nördlichen Europa, II’, Annalen der Physik und Chemie (1825) 80, pp. 309–330Google Scholar.
37 Hansteen, Christopher, ‘Diurnal variation of the needle’, Edinburgh Philosophical Journal (1821) 4, p. 199Google Scholar; Hansteen, , ‘Account of the recent magnetical discoveries of Professor Hansteen’, Edinburgh Philosophical Journal (1821) 4, pp. 295–300Google Scholar.
38 David Brewster to Christopher Hansteen, 10 June 1821, UO.
39 Sabine, Edward, ‘Observations on the dip and variation of the magnetic needle, and on the intensity of the magnetic force: made during the late voyage in search of a North West Passage’, Philosophical Transactions of the Royal Society of London (1819) 109, pp. 132–144Google Scholar; Sabine, , ‘An account of experiments to determine the amount of the dip of the magnetic needle in London, in August 1821: with remarks on the instruments which are usually employed in such determinations’, Philosophical Transactions of the Royal Society of London (1822) 112, pp. 1–21Google Scholar; Reingold, Nathan, ‘Edward Sabine’, in Gillispie, Charles Coulston (ed.), Dictionary of Scientific Biography, vol. 12, New York: Charles Scribner's Sons, 1975, pp. 49–53Google Scholar.
40 Sabine, Edward, An Account of Experiments to Determine the Figure of the Earth, London: John Murray, 1825Google Scholar.
41 Hansteen, Christopher, ‘Engelsk videnskabelig Expedition i Polarhavet i 1823’, Magazin for Naturvidenskaberne (1824) 3, pp. 148–151Google Scholar.
42 Hansteen, Christopher, ‘Forsög til et Magnetisk Hældningskart, konstruert efter Iagttagelsene paa de seneste Engelske Nordvest-Expeditioner under Captainerne Ross og Parry’, Magazin for Naturvidenskaberne (1825) 5, pp. 203–212Google Scholar; Hansteen, , ‘Versuch einer magnetischen Neigungskarte, gezeichnet nach den Beobachtungen auf den letzten englischen Nordpol-Expeditionen unter Ross und Parry’, Annalen der Physik und Chemie (1825) 80, pp. 277–286Google Scholar.
43 Edward Sabine to Christopher Hansteen, 8 August 1825, UO.
44 Christopher Hansteen to Edward Sabine, 25 December 1825, the National Archives, London (subsequently NA), Records of the Meteorological Office, Sir Edward Sabine: Correspondence and papers, BJ 3/3, 50 C.
45 Hansteen, Christopher, ‘Capt. Sabines Pendel-Iagttagelser’, Magazin for Naturvidenskaberne (1825) 6, pp. 309–310Google Scholar.
46 Subsequent quotations from Christopher Hansteen to Edward Sabine, 16 February 1826, NA, BJ 3/3, 51 A–D.
47 Hansteen, Christopher, ‘Magnetiske Intensitets-Iagttagelser’, Magazin for Naturvidenskaberne (1826) 7, pp. 342–343Google Scholar.
48 Hansteen, Christopher, ‘Nogle Tillæg til Afhandlingen om Magnetiske Intensitets-Iagttagelser i Magazinets 4de og 5te Bind’, Magazin for Naturvidenskaberne (1825) 6, pp. 281–301Google Scholar.
49 Edward Sabine, ‘Report on the variations of the magnetic intensity observed at different points of the Earth's surface’, Report of the Seventh Meeting of the British Association for the Advancement of Science, Held at Liverpool in September 1837, London: John Murray, 1838, pp. 1–85, 12.
50 Hansteen, Christopher, ‘Isodynamiske Linier for den hele magnetiske Kraft’, Magazin for Naturvidenskaberne (1826) 7, pp. 76–111Google Scholar.
51 Christopher Hansteen to Edward Sabine, 16 February 1826, NA, BJ 3/3, 51 D.
52 Sabine, op. cit. (40), p. 495.
53 Christopher Hansteen to Edward Sabine, 13 May 1826, NA, BJ 3/3, 52 A.
54 Edward Sabine to Christopher Hansteen, 3 July 1826, UO.
55 Miller, op. cit. (15), p. 122.
56 Sabine, Edward, ‘Experiments to ascertain the ratio of the magnetic forces acting on a needle suspended horizontally, in Paris and in London’, Philosophical Transactions of the Royal Society of London (1828) 118, pp. 1–14Google Scholar.
57 Edward Sabine to Christopher Hansteen, 4 July 1827, UO; Hansteen, Christopher, ‘Den magnetiske Intensitets Aftagelse paa forskjellige Steder I Europa, bestemt ved forskjellige Iagttagelser af Capt. Edw. Sabine og Professor Chr. Hansteen, meddelt’, Magazin for Naturvidenskaberne (1827) 8, pp. 299–313Google Scholar.
58 Edward Sabine to Christopher Hansteen, 4 July 1827, UO; Hansteen, op. cit. (57), p. 303.
59 Quetelet, Adolphe, ‘Recherches sur l'intensité magnétique de différens lieux de l'Allemagne et des Pay-Bas’, in Nouveaux mémoires de l'Académie royale des sciences et belles-lettres de Bruxelles, vol. 6, Brussels: M. Hayez, 1830, pp. 1–18Google Scholar; Quetelet, , ‘Recherches sur l'intensité magnétique en Suisse et en Italie’, in Nouveaux mémoires, vol. 6, op. cit., pp. 1–16Google Scholar.
60 Joseph Henry to Lewis Beck, 21 September 1827, in The Papers of Joseph Henry, 5 vols. (ed. Nathan Reingold et al.), Washington, DC: Smithsonian Institution Press, 1972–1988, vol. 1, pp. 196–199; Moyer, Albert E., Joseph Henry: The Rise of an American Scientist, Washington, DC: Smithsonian Institution Press, 1997, pp. 57–58Google Scholar; Hansteen, Christopher, ‘On the aurora borealis and polar fogs’, Edinburgh Philosophical Journal (1825) 12, pp. 83–93Google Scholar, 235–238; Hansteen, , ‘On the number and situation of the magnetic poles of the Earth’, Edinburgh Philosophical Journal (1825) 12, pp. 328–334Google Scholar.
61 Sabine, Edward, ‘Observations on the magnetism of the Earth, especially of the Arctic regions; in a letter from Capt. Edward Sabine, to Professor Renwick’, American Journal of Science and Arts (1830) 17, pp. 145–156Google Scholar, 156; Henry, op. cit. (60), vol. 1, pp. 289 ff.; Moyer, op. cit. (60), p. 121.
62 Henry, Joseph, ‘On a disturbance of the Earth's magnetism, in connection with the appearance of an aurora borealis, as observed at Albany, April 19, 1831’, American Journal of Science and Arts (1832) 22, pp. 143–155Google Scholar.
63 James Renwick Sr to Joseph Henry, 4 August 1833, in Henry, op. cit. (60), vol. 2, p. 87.
64 Bache, Alexander Dallas and Courtenay, Edward H., ‘On the relative horizontal intensities of terrestrial magnetism at several places in the United States, with the investigation of corrections for temperature, and comparisons of the method of oscillations in full and in rarified air’, Transactions of the American Philosophical Society (1837) 5, pp. 427–457Google Scholar, 430–431.
65 Bache, Alexander Dallas, ‘Observations of the magnetic intensity at twenty-one stations in Europe’, Transactions of the American Philosophical Society (1841) 7, pp. 75–100Google Scholar; Good, Gregory, ‘Geomagnetics and scientific institutions in 19th-century America’, Eos: Transactions of the American Geophysical Union (1985) 66, pp. 524–526Google Scholar.
66 Philip Parker King to Christopher Hansteen, 6 November and 4 December 1826, UO; King, ‘Magnetiske Intensitets-Iagttagelser langs Sydamerikas Kyster, af Capit. Ph. P. King’, Magazin for Naturvidenskaberne (1827) 8, pp. 106–120.
67 Edward Sabine quoted from King, Philip Parker, Narrative of the Surveying Voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, Describing Their Examination of the Southern Shores of South America, and the Beagle’s Circumnavigation of the Globe. Proceedings of the First Expedition, 1826–30, under the Command of Captain P. Parker King, R.N., F.R.S., London: Henry Colburn, 1839, p. 502Google Scholar.
68 David Brewster to Christopher Hansteen, 7 November 1826, UO.
69 Morrison-Low, Alison, ‘The soldier-astronomer in Scotland: Thomas Makdougall Brisbane's scientific work in the northern hemisphere’, Historical Records of Australian Science (2004) 15, pp. 151–176CrossRefGoogle Scholar.
70 Simon Schaffer, ‘Keeping the books at Parramatta’, in Aubin, Bigg and Sibum, op. cit. (2), pp. 118–147.
71 All quotes from Dunlop, James, ‘An account of observations made in Scotland on the distribution of magnetic intensity’, Transactions of the Royal Society of Edinburgh (1834) 12, pp. 2–5Google Scholar.
72 Brisbane quoted from Dunlop, op. cit. (71), pp. 1–2.
73 Rutledge, Sharon, ‘For further consideration: Mr James Dunlop, Esq.’ Journal & Proceedings of the Royal Society of New South Wales (2009) 142, pp. 17–28CrossRefGoogle Scholar.
74 James Forbes to Christopher Hansteen, 13 March 1832, UO. For details on Brewster's defeat by Forbes in the competition for the natural philosophy chair at the University of Edinburgh in 1836, see Steven Shapin, ‘Brewster and the Edinburgh career in Science’, in Morrison-Low and Christie, op. cit. (23), pp. 17–23.
75 Hansteen, Christopher, ‘Ueber die magnetische Intensität der Erde’, Astronomische Nachrichten (1831) 9, pp. 304–312Google Scholar.
76 Orange, A.D. (Derek), ‘The origins of the British Association for the Advancement of Science’, BJHS (1972) 6, pp. 152–176Google Scholar; McLeod, Roy and Collins, Peter (eds.), The Parliament of Science: The British Association for the Advancement of Science 1831–1981, Northwood: Science Reviews, 1981Google Scholar; Morrell and Thackray, op. cit. (6).
77 First Report of the Proceedings, Recommendations, and Transactions of the British Association for the Advancement of Science, York: Thomas Wilson and Sons, 1832, p. vi, also pp. 51–52.
78 Scoresby, William, ‘Description of a magnetimeter, being a new instrument for measuring magnetic attractions, and finding the dip of the needle; with an account of experiments made with it’, Transactions of the Royal Society of Edinburgh (1823) 9, pp. 243–258Google Scholar; Traill, Thomas Stewart, ‘Experiments on the intensity of terrestrial magnetism, at Liverpool and Manchester, with Hansteen's needles’, Report of the Second Meeting of the British Association for the Advancement of Science, Held at Oxford in 1832, London: John Murray, 1832, p. 557Google Scholar; see Morrell and Thackray, op. cit. (6), p. 525.
79 Forbes, James D., ‘Account of some experiments made in different parts of Europe, on terrestrial magnetic intensity, particularly with reference to the effect of heights’, Transactions of the Royal Society of Edinburgh (1840) 14, pp. 1–29Google Scholar, 2.
80 Cawood, op. cit. (6), p. 493.
81 Cawood, op. cit. (6), p. 500–503.
82 Edward Sabine, ‘On the phænomena of terrestrial magnetism: being an abstract of the Magnetismus der Erde of Professor Ch. Hansteen’, Report of the Fifth Meeting of the British Association for the Advancement of Science, Held at Dublin in August 1835, London: John Murray, 1836, pp. 61–90. See Morrell and Thackray, op. cit. (6), pp. 354–355.
83 Lloyd, Humphrey, Sabine, Edward and Ross, James Clarke, ‘Observations on the direction and intensity of the terrestrial magnetic force in Ireland’, Report of the Fifth Meeting, op. cit. (82), pp. 117–162Google Scholar, 117.
84 Edward Sabine, ‘Observations on the direction and intensity of the terrestrial magnetic force in Scotland’, Report of the Sixth Meeting of the British Association for the Advancement of Science, Held at Bristol in August 1836, London: John Murray, 1837, pp. 97–119, 110.
85 Edward Sabine, ‘A memoir on the magnetic isoclinal and isodynamic lines in the British Islands, from observations by Professors Humphrey Lloyd and John Phillips, Robert Were Fox, Esq., Captain James Clark Ross, R.N. , and Major Edward SabineR.A.’, Report of the Eight Meeting of the British Association for the Advancement of Science, Held at Newcastle in September 1838, London: John Murray, 1839, pp. 49–196, 148.
86 Cannon, Susan Faye, Science in Culture: The Early Victorian period, New York: Dawson and Science History Publications, 1978, p. 81Google Scholar; Morrell and Thackray, op. cit. (6), pp. 354, 524.
87 von Humboldt, Alexander, ‘Ueber die Mittel, die Ergründung einiger Phänomene des tellurischen Magnetismus zu erleichtern’, Annalen der Physik und Chemie (1829), 15, pp. 319–336Google Scholar.
88 von Humboldt, Alexander, ‘Beobachtungen der Intensität magnetischer Kräfte und der magnetischen Neigung, angestellt in den Jahren 1798 bis 1803’, Annalen der Physik und Chemie (1829), 15, pp. 336–355Google Scholar; see Hansteen, op. cit. (3), pp. 67–73.
89 Honigmann, Peter, ‘Über Alexander von Humboldts geophysicalische Instrumente auf seiner russisch-sibirischen Reise’, Gerlands Beiträge zur Geophysik (1982) 91, pp. 185–199Google Scholar.
90 von Humboldt, Alexander, ‘On the advancement of the knowledge of terrestrial magnetism, by the establishment of magnetic stations and corresponding observations’, London and Edinburgh Philosophical Magazine (1836) 9, pp. 42–53Google Scholar, 48.