Haematite, 22, 51. Hali Abbas ('Ali ibn Al 'Abbás, _Al Masúfí_), 2, 6. Hannibal Rosetius Calaber, 3. Hariot, Thomas, 7. Heat, effect of on loadstone, 66, 67, 93, 123, 124. Helmshuda, 167. Heraclea, the city of, 8. Heraclean stone, or stone of Hercules, 8, 43, 61, 169. Heraclides, 214. Heraclitus, 208. Hermes, 209. Hermolaus Barbarus, 3. Hero of Alexandria, 58. Hipparchus, 213, 214, 234, 235, 237. Hippocrates, 8, 35, 51, 61. horizon, the magnetick, defined, 80. Horto, Gartias ab, 32. Horus, the bone of, or _Os Ori_, 9. hot iron not magnetick, 66. Hues, Robert, 7. Hugo Grotius, 167, 168. Inclination. _See_ dip. interposition of bodies, 53, 66, 83, 85, 89, 137. iris gem, the, 48. iron, its nature and occurrence, 19, 20, 22, 25. filings of, 37, 69, 90, 91, 92, 104. its various names and qualities, 23, 33, 36. its various uses, 23, 24, 39, 86, 90, 95. medical uses of, 33, 35. surpasses loadstone, 69, 95. verticity in, 85, 123, 139. iron ore is magnetick, 18, 27, 38, 43. has poles, 28. islands, magnetick influence of, 5, 153,161. Jacobus Severtius, 5. jet, 47, 48, 53, 55, 86. Joannes Baptista Porta. _See_ Porta. Joannes Baptista Montanus, 2. Joannes Costæus. _See_ Costæus. Joannes Franciscus Offusius, 46. Joannes Goia. _See_ Gioia. Joannes Langius, 3. Joannes Taisner, or Taisnier. _See_ Taisnier. Jofrancus Offusius, 46. Josephus Acosta, 5. Julius Cæsar Moderatus, 141. Julius Cæsar Scaliger. _See_ Scaliger. Kendall, Abraham, 7, 178. Korrah, Thebitius Ben. _See_ Bencora. Lactantius, Lucius, 219. Lagos, Rodriguez de, 177. Langius, Joannes, 3. _lapis magnetis_, 8. _lapis specularis_, muscovy stone, or mica, 11, 48, 52. latitude in relation to dip, 196, 200. Leonardus (or Leonhardus), Camillus, 3. Levinus Lemnius, 3. {244} lifting power of loadstones, 86, 89, 97. lily of the compass, 117, 152, 165, 177. liquids, electrical attraction of, 55. attraction on surface of, 57. Livio Sanuto, 5, 153, 167. loadstone armed and unarmed, 86, 87, 88. as medicine, 32. in plasters, 33. rock, the, 5, 6, 18, 116, 152. various names of, 11. colours of, 9, 10, 27. various sources of, 8, 25, 32. London, magnetick variation at, 154, 163. longitude, magnetick finding at, 166. long magnets, advantage of, 82, 83, 99, 101 Lucania, fall of meteorick stones in, 26. Lucas Gauricus, 7. Lucretius, 2, 3, 8, 49, 61. Lusitanus, Amatus, 2. Lynschoten, Hugo van, *iiij.