The Lodestone: History, physics, and formation

Annals of Science

Volumn 61, Issue 3, 2004, Pages 273-319

  Mills, Allan A ^a  

^a UNIVERSITY OF LEICESTER   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ANNEALING; CARBON STEEL; CRYSTALLOGRAPHY; DAMPING; ELECTROMAGNETS; FERROMAGNETISM; FORMING; MAGNETIC FIELDS; MAGNETIC PROPERTIES; PERMANENT MAGNETS; POLARIZATION; TRACE ELEMENTS;

CRYSTALLOGRAPHIC DIFFERENCES; MAGNETIC SATURATION; MATHEMATICAL TESTS; NATURAL LODESTONES;

MAGNETITE;

EID: 3442899616     PISSN: 00033790     EISSN: None     Source Type: Journal    
DOI: 10.1080/00033790310001642812     Document Type: Article

References (108)

1. Joseph Ennemoser, Der Magnetismus im Verhältnisse zur Natur und Religion (Stuttgart, 1842). Albert Radl, Der Magnetstein in der Antike: Quellen und Zusammenhänge (Stuttgart, 1988). Gudrun Stecher, Magnetismus im Mittelalter: von den Fahigkeiten und der Verwendung des Magneten in Dichtung, Alltag und Wissenschaft (Kummerle, 1995).
2. Joseph Ennemoser, Der Magnetismus im Verhältnisse zur Natur und Religion (Stuttgart, 1842). Albert Radl, Der Magnetstein in der Antike: Quellen und Zusammenhänge (Stuttgart, 1988). Gudrun Stecher, Magnetismus im Mittelalter: von den Fahigkeiten und der Verwendung des Magneten in Dichtung, Alltag und Wissenschaft (Kummerle, 1995).
3. Joseph Ennemoser, Der Magnetismus im Verhältnisse zur Natur und Religion (Stuttgart, 1842). Albert Radl, Der Magnetstein in der Antike: Quellen und Zusammenhänge (Stuttgart, 1988). Gudrun Stecher, Magnetismus im Mittelalter: von den Fahigkeiten und der Verwendung des Magneten in Dichtung, Alltag und Wissenschaft (Kummerle, 1995).
4. Petrus Peregrinus, Epistola de Magnete (1269), MS reproduced by Quaritch (London, 1900), trans. by Silvanus Thompson (London: Chiswick Press, 1902). A more accessible source is Mottelay (note 11).
5. Agricola, De Natura Fossilium (Basle, 1546), trans. by M. C. and J. A. Bandy, Geological Society of America, Special Paper 63, (1953). Agricola, De Re Metallica (Basle, 1556), trans. by Hoover (London, 1912). J. B. Porta, Magia Naturalis (Naples 1558), trans. as Natural Magic (London, 1658), Book VII: The Magnet. Robert Norman, The Newe Attractive: Containing a Short Discourse of the Magnes or Lodestone ... (London, 1581).
6. Agricola, De Natura Fossilium (Basle, 1546), trans. by M. C. and J. A. Bandy, Geological Society of America, Special Paper 63, (1953). Agricola, De Re Metallica (Basle, 1556), trans. by Hoover (London, 1912). J. B. Porta, Magia Naturalis (Naples 1558), trans. as Natural Magic (London, 1658), Book VII: The Magnet. Robert Norman, The Newe Attractive: Containing a Short Discourse of the Magnes or Lodestone ... (London, 1581).
7. Agricola, De Natura Fossilium (Basle, 1546), trans. by M. C. and J. A. Bandy, Geological Society of America, Special Paper 63, (1953). Agricola, De Re Metallica (Basle, 1556), trans. by Hoover (London, 1912). J. B. Porta, Magia Naturalis (Naples 1558), trans. as Natural Magic (London, 1658), Book VII: The Magnet. Robert Norman, The Newe Attractive: Containing a Short Discourse of the Magnes or Lodestone ... (London, 1581).
8. Agricola, De Natura Fossilium (Basle, 1546), trans. by M. C. and J. A. Bandy, Geological Society of America, Special Paper 63, (1953). Agricola, De Re Metallica (Basle, 1556), trans. by Hoover (London, 1912). J. B. Porta, Magia Naturalis (Naples 1558), trans. as Natural Magic (London, 1658), Book VII: The Magnet. Robert Norman, The Newe Attractive: Containing a Short Discourse of the Magnes or Lodestone ... (London, 1581).
9. Agricola, De Natura Fossilium (Basle, 1546), trans. by M. C. and J. A. Bandy, Geological Society of America, Special Paper 63, (1953). Agricola, De Re Metallica (Basle, 1556), trans. by Hoover (London, 1912). J. B. Porta, Magia Naturalis (Naples 1558), trans. as Natural Magic (London, 1658), Book VII: The Magnet. Robert Norman, The Newe Attractive: Containing a Short Discourse of the Magnes or Lodestone ... (London, 1581).
10. Agricola, De Natura Fossilium (Basle, 1546), trans. by M. C. and J. A. Bandy, Geological Society of America, Special Paper 63, (1953). Agricola, De Re Metallica (Basle, 1556), trans. by Hoover (London, 1912). J. B. Porta, Magia Naturalis (Naples 1558), trans. as Natural Magic (London, 1658), Book VII: The Magnet. Robert Norman, The Newe Attractive: Containing a Short Discourse of the Magnes or Lodestone ... (London, 1581).
11. Agricola, De Natura Fossilium (Basle, 1546), trans. by M. C. and J. A. Bandy, Geological Society of America, Special Paper 63, (1953). Agricola, De Re Metallica (Basle, 1556), trans. by Hoover (London, 1912). J. B. Porta, Magia Naturalis (Naples 1558), trans. as Natural Magic (London, 1658), Book VII: The Magnet. Robert Norman, The Newe Attractive: Containing a Short Discourse of the Magnes or Lodestone ... (London, 1581).
12. William Gilbert, De Magnete (London, 1600), trans. by P. Fleury Mottelay (1893; New York: Dover, 1958). Silvanus P. Thompson, Gilbert of Colchester (London, 1891). E. B. Gilberd and Lord Penny William Gilberd (Colchester: Castle Museum, 1970). The last of these works claims that 'Gilberd' is the correct spelling, based on an extant signature.
13. William Gilbert, De Magnete (London, 1600), trans. by P. Fleury Mottelay (1893; New York: Dover, 1958). Silvanus P. Thompson, Gilbert of Colchester (London, 1891). E. B. Gilberd and Lord Penny William Gilberd (Colchester: Castle Museum, 1970). The last of these works claims that 'Gilberd' is the correct spelling, based on an extant signature.
14. William Gilbert, De Magnete (London, 1600), trans. by P. Fleury Mottelay (1893; New York: Dover, 1958). Silvanus P. Thompson, Gilbert of Colchester (London, 1891). E. B. Gilberd and Lord Penny William Gilberd (Colchester: Castle Museum, 1970). The last of these works claims that 'Gilberd' is the correct spelling, based on an extant signature.
15. Marke Ridley, A Short Treatise of Magnetical Bodies and Motions (London, 1613).
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17. Athanasius Kircher, Magnes (Cologne, 1643), and Magneticum Naturae Regnum (Rome, 1667).
18. Athanasius Kircher, Magnes (Cologne, 1643), and Magneticum Naturae Regnum (Rome, 1667).
19. Dalancé, Traitte de l'Aiman (1687).
20. Robert Boyle, Experimenta & Observationes Physicae (London, 1691).
21. Servington Savery, 'Magnetical Observations and Experiments', Philosophical Transactions, 36 (1730), 295-340.
22. P. F. Mottelay, Bibliographical History of Electricity and Magnetism (London, 1922).
23. Savery (note 10). Gowan Knight, 'An Account of Some Magnetical Experiments ...' Philosophical Transactions, 43 (1744), 161-66, and 44 (1744), 656-72. J. Michell, A Treatise of Artificial Magnets (Cambridge, 1750). J. Canton, 'A Method of Making Artificial Magnets Without the Use of Natural Ones', Philosophical Transactions, 47 (1753), 31-38. J. Fothergill, 'An Account of the Magnetical Machine Contrived by the Late Dr Gowin Knight', Philosophical Transactions, 66 (1776), 591-99. Tiberius Cavallo, A Treatise on Magnetism (London, 1800).
24. Savery (note 10). Gowan Knight, 'An Account of Some Magnetical Experiments ...' Philosophical Transactions, 43 (1744), 161-66, and 44 (1744), 656-72. J. Michell, A Treatise of Artificial Magnets (Cambridge, 1750). J. Canton, 'A Method of Making Artificial Magnets Without the Use of Natural Ones', Philosophical Transactions, 47 (1753), 31-38. J. Fothergill, 'An Account of the Magnetical Machine Contrived by the Late Dr Gowin Knight', Philosophical Transactions, 66 (1776), 591-99. Tiberius Cavallo, A Treatise on Magnetism (London, 1800).
25. Savery (note 10). Gowan Knight, 'An Account of Some Magnetical Experiments ...' Philosophical Transactions, 43 (1744), 161-66, and 44 (1744), 656-72. J. Michell, A Treatise of Artificial Magnets (Cambridge, 1750). J. Canton, 'A Method of Making Artificial Magnets Without the Use of Natural Ones', Philosophical Transactions, 47 (1753), 31-38. J. Fothergill, 'An Account of the Magnetical Machine Contrived by the Late Dr Gowin Knight', Philosophical Transactions, 66 (1776), 591-99. Tiberius Cavallo, A Treatise on Magnetism (London, 1800).
26. Savery (note 10). Gowan Knight, 'An Account of Some Magnetical Experiments ...' Philosophical Transactions, 43 (1744), 161-66, and 44 (1744), 656-72. J. Michell, A Treatise of Artificial Magnets (Cambridge, 1750). J. Canton, 'A Method of Making Artificial Magnets Without the Use of Natural Ones', Philosophical Transactions, 47 (1753), 31-38. J. Fothergill, 'An Account of the Magnetical Machine Contrived by the Late Dr Gowin Knight', Philosophical Transactions, 66 (1776), 591-99. Tiberius Cavallo, A Treatise on Magnetism (London, 1800).
27. Savery (note 10). Gowan Knight, 'An Account of Some Magnetical Experiments ...' Philosophical Transactions, 43 (1744), 161-66, and 44 (1744), 656-72. J. Michell, A Treatise of Artificial Magnets (Cambridge, 1750). J. Canton, 'A Method of Making Artificial Magnets Without the Use of Natural Ones', Philosophical Transactions, 47 (1753), 31-38. J. Fothergill, 'An Account of the Magnetical Machine Contrived by the Late Dr Gowin Knight', Philosophical Transactions, 66 (1776), 591-99. Tiberius Cavallo, A Treatise on Magnetism (London, 1800).
28. Savery (note 10). Gowan Knight, 'An Account of Some Magnetical Experiments ...' Philosophical Transactions, 43 (1744), 161-66, and 44 (1744), 656-72. J. Michell, A Treatise of Artificial Magnets (Cambridge, 1750). J. Canton, 'A Method of Making Artificial Magnets Without the Use of Natural Ones', Philosophical Transactions, 47 (1753), 31-38. J. Fothergill, 'An Account of the Magnetical Machine Contrived by the Late Dr Gowin Knight', Philosophical Transactions, 66 (1776), 591-99. Tiberius Cavallo, A Treatise on Magnetism (London, 1800).
29. David Brewster, 'A Treatise on Magnetism', in Encyclopaedia Britannica, 7th ed (1837). J. B. Kramer, 'The Early History of Magnetism', Transactions of the Newcomen Society, 14 (1933-34), 183-200. Alfred Still, Soul of Lodestone: The Background of Magnetical Science (New York, 1946). E. N. da C. Andrade, 'The Early History of the Permanent Magnet', Endeavour, 17 (1958), 22-30. L. W. McKeehan, Magnets (New York, 1967).
30. David Brewster, 'A Treatise on Magnetism', in Encyclopaedia Britannica, 7th ed (1837). J. B. Kramer, 'The Early History of Magnetism', Transactions of the Newcomen Society, 14 (1933-34), 183-200. Alfred Still, Soul of Lodestone: The Background of Magnetical Science (New York, 1946). E. N. da C. Andrade, 'The Early History of the Permanent Magnet', Endeavour, 17 (1958), 22-30. L. W. McKeehan, Magnets (New York, 1967).
31. David Brewster, 'A Treatise on Magnetism', in Encyclopaedia Britannica, 7th ed (1837). J. B. Kramer, 'The Early History of Magnetism', Transactions of the Newcomen Society, 14 (1933-34), 183-200. Alfred Still, Soul of Lodestone: The Background of Magnetical Science (New York, 1946). E. N. da C. Andrade, 'The Early History of the Permanent Magnet', Endeavour, 17 (1958), 22-30. L. W. McKeehan, Magnets (New York, 1967).
32. David Brewster, 'A Treatise on Magnetism', in Encyclopaedia Britannica, 7th ed (1837). J. B. Kramer, 'The Early History of Magnetism', Transactions of the Newcomen Society, 14 (1933-34), 183-200. Alfred Still, Soul of Lodestone: The Background of Magnetical Science (New York, 1946). E. N. da C. Andrade, 'The Early History of the Permanent Magnet', Endeavour, 17 (1958), 22-30. L. W. McKeehan, Magnets (New York, 1967).
33. David Brewster, 'A Treatise on Magnetism', in Encyclopaedia Britannica, 7th ed (1837). J. B. Kramer, 'The Early History of Magnetism', Transactions of the Newcomen Society, 14 (1933-34), 183-200. Alfred Still, Soul of Lodestone: The Background of Magnetical Science (New York, 1946). E. N. da C. Andrade, 'The Early History of the Permanent Magnet', Endeavour, 17 (1958), 22-30. L. W. McKeehan, Magnets (New York, 1967).
34. McKeehan (note 13).
35. Joseph Needham, Science and Civilisation in China (Cambridge, 1962), IV. A. Ronan and J. Needham, The Shorter Science and Civilisation in China (Cambridge, 1986), III, ch.1. In view of the disputed period of discovery it is perhaps ironic to learn that magnetotactic bacteria were using tiny intracellular grains of magnetite to determine direction in the remote geological past. See R. F. Blakemore and R. B. Frankel, 'Magnetic Navigation in Bacteria', Scientific American, 245 (December) (1981), 42-49.
36. Joseph Needham, Science and Civilisation in China (Cambridge, 1962), IV. A. Ronan and J. Needham, The Shorter Science and Civilisation in China (Cambridge, 1986), III, ch.1. In view of the disputed period of discovery it is perhaps ironic to learn that magnetotactic bacteria were using tiny intracellular grains of magnetite to determine direction in the remote geological past. See R. F. Blakemore and R. B. Frankel, 'Magnetic Navigation in Bacteria', Scientific American, 245 (December) (1981), 42-49.
37. Joseph Needham, Science and Civilisation in China (Cambridge, 1962), IV. A. Ronan and J. Needham, The Shorter Science and Civilisation in China (Cambridge, 1986), III, ch.1. In view of the disputed period of discovery it is perhaps ironic to learn that magnetotactic bacteria were using tiny intracellular grains of magnetite to determine direction in the remote geological past. See R. F. Blakemore and R. B. Frankel, 'Magnetic Navigation in Bacteria', Scientific American, 245 (December) (1981), 42-49.
38. See Agricola, De Re Metallica (1556) (note 3).
39. See Norman (note 3).
40. Calculated values for the seven elements of the geomagnetic field at any site on any given date are obtainable from the National Geophysical Data Center, Colorado, USA at www.ngdc.noaa.gov. It must be borne in mind that these model values are subject to small and unpredictable variations due to solar activity and local influences.
41. Needham (note 15).
42. G. W. C. Kaye and T. H. Laby, Tables of Physical and Chemical Constants (London, 1966).
43. McKeehan (note 13).
44. Johann von Lamont, Handbuch des Magnetismus (1856, 1867).
45. Kircher, 1667 (note 7), Dalencé, 1687 (note 8), Cavallo, 1800 (note 12).
46. P. D. Marianini, 'Armed Magnets and Some Methods of Magnetization', Nuovo Cimento, 4 (1856) 231-62.
47. Nehemiah Grew, Catalogue and Description of the Natural and Artificial Rarities Belonging to the Royal Society ... (London, 1681).
48. A. de la Hire, 'A New Sort of Magnetical Compass', Philosophical Transactions, 16 (1687), 344-51.
49. Isaac Newton, Principia (London, 1687), Book 3, Prop.6, Theorem 6, Cor.5.
50. Journal Book of the Royal Society, 1702-1714, 10, 373 (for 20 March 1712).
51. Francis Hawksbee, 'An Account of the Experiments Concerning the Proportion of the Power of the Load-stone at Different Distances', Philosophical Transactions, 27 (1712), 506-11 and Figure4 on separate plate.
52. Brook Taylor, 'An Account of an Experiment Made by Dr Brook Taylor Assisted by Mr Hawksbee, in Order to Discover the Law of the Magnetical Attraction', Philosophical Transactions, 29 (1712), 294-95.
53. P. Musschenbroek and J. T. Desaguliers, 'De Viribus Magneticis', Philosophical Transactions, 33 (1724-5), 370-78.
54. Robert Palter, 'Early Measurement of Magnetic Force', Isis, 63 (1972), 544-58.
55. J. K. F. Gauss, Intensitas Vis Magneticae Terrestris (1832), Not easily accessible - see C. C. Gillispie (ed.), Dictionary of Scientific Biography (New York, 1972), v, 298-315. A portion is reproduced in F. Magie, Source Book in Physics (New York, 1935), pp. 519-24.
56. J. K. F. Gauss, Intensitas Vis Magneticae Terrestris (1832), Not easily accessible - see C. C. Gillispie (ed.), Dictionary of Scientific Biography (New York, 1972), v, 298-315. A portion is reproduced in F. Magie, Source Book in Physics (New York, 1935), pp. 519-24.
57. J. K. F. Gauss, Intensitas Vis Magneticae Terrestris (1832), Not easily accessible - see C. C. Gillispie (ed.), Dictionary of Scientific Biography (New York, 1972), v, 298-315. A portion is reproduced in F. Magie, Source Book in Physics (New York, 1935), pp. 519-24.
58. J. Deuchar, 'Large Loadstones', Memoirs of the Wernerian Natural History Society, Edinburgh, 4 (1821), 386-95 and Plate XII.
59. Mary Holbrook, Science Preserved (London, 1992).
60. See their website www.mhs.ox.ac.uk
61. A. Q. Morton and J. A. Wess, Public and Private Science, (Oxford, 1993). Also NMSI website.
62. Paolo Brenni, Gli strumenti di fisica dell'Istituto Tecnico Toscano. Elettricita e Magnetismo (Florence, 2000).
63. J. F. Williams, 'The Igneous Rocks of Arkansas', in Arkansas Geological Survey, Annual report for 1890.
64. R. L. Erikson and L. V. Blade, 'Geochemistry and Petrology of the Alkalic Igneous Complex at Magnet Cove, Arkansas', USGS Professional Paper 425 (1963).
65. This site is now closed to public collecting. It is rumoured that both raw and tumble-polished pieces of ordinary magnetite from various localities have occasionally been artificially magnetized by exposure to a strong magnetic field and then sold as charms.
66. This agrees with Still (note 13), who writes 'The lodestone found at Magnet Cove in Arkansas is frequently in the form of brown pebbles turned up by the plow.'
67. Ward's Natural Science, PO Box 92912, Rochester, NY.
68. J. H. Poynting and J. J. Thomson, A Textbook of Physics (London, 1920), IV: Electricity and Magnetism.
69. W. H. Newhouse, 'The Identity and Genesis of Lodestone Magnetite', Economic Geology, 24 (1929), 62-67.
70. J. Gruner, 'The Identity and Genesis of Lodestone Magnetite', Economic Geology, 24 (1929), 771-75.
71. C. Davis, 'Geological Significance of Magnetic Properties of Minerals', Economic Geology, 30 (1935), 655-62. Repeated in US Bureau of Mines Bulletin, 425 (1941), 362-66.
72. C. Davis, 'Geological Significance of Magnetic Properties of Minerals', Economic Geology, 30 (1935), 655-62. Repeated in US Bureau of Mines Bulletin, 425 (1941), 362-66.
73. C. E. N. Bromehead, 'Ship's Loadstones', Mineralogical Magazine, 28 (1948), 429-37.
74. P. Weiss, 'Magnetization of Crystallised Magnetite', Comptes Rendus Academie des Sciences, Paris, 122 (1896), 1405-09.
75. E. Wilson and E. F. Herroun, 'The Magnetic Properties of Varieties of Magnetite', Proceedings of the Physical Society, 31 (1919), 299-318.
76. D. Strangway, History of the Earth's Magnetic Field (New York, 1970).
77. P. J. Wasilewski, 'Lodestone - Nature's Own Permanent Magnet', NASA-GSFC, X691-76-110 (1976). P. J. Wasilewski, 'Magnetic and Microstructural Properties of Some Lodestones', Physics of the Earth and Planetary Interiors, 15 (1977), 349-62.
78. P. J. Wasilewski, 'Lodestone - Nature's Own Permanent Magnet', NASA-GSFC, X691-76-110 (1976). P. J. Wasilewski, 'Magnetic and Microstructural Properties of Some Lodestones', Physics of the Earth and Planetary Interiors, 15 (1977), 349-62.
79. M. Blackman and N. D. Lisgarten, 'On the Intensity of Magnetisation of Lodestones', Journal of Magnetism and Magnetic Materials, 30 (1982), 269-72. M. Blackman, 'The Lodestone: A Survey of the History and the Physics', Contemporary Physics, 24 (1983), 319-31.
80. M. Blackman and N. D. Lisgarten, 'On the Intensity of Magnetisation of Lodestones', Journal of Magnetism and Magnetic Materials, 30 (1982), 269-72. M. Blackman, 'The Lodestone: A Survey of the History and the Physics', Contemporary Physics, 24 (1983), 319-31.
81. F. Tyler, A Laboratory Manual of Physics (London, 1959).
82. D. Owen, To Find the Magnetic Neutral Points of a Bar Magnet in the Earth's Magnetic Field', in The Science Master's Book, ed. by G. H. J. Adlam, S. R. Humby and G. N. Pingriff (London, 1950), Ser. III, Part I (Physics), pp. 167-69.
83. G. R. Noakes, A Textbook of Electricity and Magnetism (London, 1947)
84. M. Nelkon, Advanced Level Magnetism and Electricity (London, 1954).
85. Wilson and Herroun (note 49).
86. T. Nagata, Rock Magnetism (Tokyo, 1953, 1961)
87. Wasilewski (note 51).
88. Blackman and Lisgarten (note 52).
89. Noakes (note 55).
90. Tyler (note 53).
91. Tyler (note 53).
92. Andrew Putnis, Introduction to Mineral Sciences (Cambridge, 1992).
93. E. Köster, 'Particulate Media', in Magnetic Recording Technology, ed. by C. D. Mee and E. D. Daniel (New York, 1995), ch. 3.
94. See Brewster (note 13).
95. F. Pockels, 'Über das magnetische Verhalten einiger basaltischer Gesteine', Annalen der Physikalische Chemie, 63 (1837), 195-201. 'Bestimmung maximaler Entladungs-strom-stärken aus ihrer magnetisirenden Wirkung', Annalen der Physikalischer Chemie, 65 (1898), 458-75, 'Über die Blitzentladungen erreichte Stromstarke', Physikalische Zeitung, 2 (1900), 306-07.
96. F. Pockels, 'Über das magnetische Verhalten einiger basaltischer Gesteine', Annalen der Physikalische Chemie, 63 (1837), 195-201. 'Bestimmung maximaler Entladungs-strom-stärken aus ihrer magnetisirenden Wirkung', Annalen der Physikalischer Chemie, 65 (1898), 458-75, 'Über die Blitzentladungen erreichte Stromstarke', Physikalische Zeitung, 2 (1900), 306-07.
97. F. Pockels, 'Über das magnetische Verhalten einiger basaltischer Gesteine', Annalen der Physikalische Chemie, 63 (1837), 195-201. 'Bestimmung maximaler Entladungs-strom-stärken aus ihrer magnetisirenden Wirkung', Annalen der Physikalischer Chemie, 65 (1898), 458-75, 'Über die Blitzentladungen erreichte Stromstarke', Physikalische Zeitung, 2 (1900), 306-07.
98. P. Gamba, 'Magnetization of Bricks by Lightning', Atti della Royale Accademia dei Lincei (Roma), 8 (1899), 316.
99. A. Cox, 'Anomalous Remanent Magnetization of Basalt', US Geological Survey Bulletin, 1083-E (1961), 131-60. R. Thompson and F. Oldfield, Environmental Magnetism (London, 1986). R. F. Butler, Paleomagnetism: Magnetic Domains to Geologic Terranes (Oxford, 1992).
100. A. Cox, 'Anomalous Remanent Magnetization of Basalt', US Geological Survey Bulletin, 1083-E (1961), 131-60. R. Thompson and F. Oldfield, Environmental Magnetism (London, 1986). R. F. Butler, Paleomagnetism: Magnetic Domains to Geologic Terranes (Oxford, 1992).
101. A. Cox, 'Anomalous Remanent Magnetization of Basalt', US Geological Survey Bulletin, 1083-E (1961), 131-60. R. Thompson and F. Oldfield, Environmental Magnetism (London, 1986). R. F. Butler, Paleomagnetism: Magnetic Domains to Geologic Terranes (Oxford, 1992).
102. Basil Schonland, The Flight of Thunderbolts (Oxford, 1964).
103. Martin A.Uman, Lightning (New York, 1969).
104. C. M. Foust and H. P. Kuehni, 'The Surge-Crest Ammeter', General Electric Review, 35 (1932) 644-48.
105. See Noakes (note 55).
106. See Schonland (note 69).
107. S. R. Logan, Fundamentals of Chemical Kinetics (London: Longman, 1996).
108. A. A. Mills, 'Armed Lodestones', accepted by the Bulletin of the Scientific Instrument Society (publication expected 2004).