Note 140 — Chapter XXVI · MAGNETIC ROCKS

A good list of references to the early German authorities on the subject is given in the American Journal of Science and Arts for 1831, vol. 20.... Zirkel in his Lehrbuch der Petrographie (1893, vol. i. p. 565) gives most of these and many more recent.... Harker in his paper below named refers to a review of the earlier literature in Verh. naturh. Vereins. Bonn, 1851, vol. 8, and to a more complete bibliography by Meli in Boll. Soc. Geol. Ital. 1881, vol. 9.... British Association Report in 1889 by Professors Rücker and Thorpe on the Magnetic State of the British Isles.... Nature for August and September, 1894, &c.... Harker on magnetic disturbances in the Isle of Skye, Proc. Cambr. Philos. Soc. vol. 10, part 5.... Skinner in Proc. Cambr. Philos. Soc. May, 1894.... Clark in Journ. Roy. Instit. Cornwall, 1890-93.... Folgheraiter in Frammenti concernanti la geofisica, Rome: referred to in Nature, July 27, 1899, and Nov. 8, 1900.