aradise_ (London, 1869, vol. i., p. 625), the loadstone rock
is an island in the far North. But this story is not one of the
Scandinavian sagas, and belongs to the Carlovingian cycle of heroic poems,
of which the chief is the _Chanson de Roland_; and Ogier le Danois is
really not a Dane but an _Ardennois_.

In the Middle-High German epic of Kudrun, the adventures of the fleet of
Queen Hilda when attracted by the loadstone mountain at Givers, in the
North Sea, are narrated at some length. (See _Kudrun, herausgegeben und
erklaert von Ernst Martin_. Halle, 1872.) One stanza will serve as a
sample:

1126. Ze Givers vor dem berge | lac daz Hilden her.
swie guot ir anker waeren, | an daz vinster mer.
magneten die steine | heten si gezogen.
ir guote segelboume | stuonden alle gebogen.

which may be rendered:

1126. At Givers before the mountain | lay Hilda's ships by.
Though good their anchors were, | upon the murky sea.
Magnets the stones were | had drawn them thither.
Their good sailing masts | stood all bent together.

Recent magnetic research has shown that while there are no magnetic
mountains that would account for the declination of the compass in general,
yet there are minor local variations that can only be accounted for by the
presence of magnetic reefs or rocks. The reader is referred to the account
of the magnetic survey of Great Britain in the _Philosophical Transactions_
(1890) by Professors Ruecker and Thorpe. The well-known rocky peak the
Riffelhorn above Zermatt, in Switzerland, produces distinct perturbations
in the direction of the compass within half a mile of its base. Such local
perturbations are regularly used in Sweden for tracing out the position of
underground lodes of iron ore. See Thalen, _Sur la Recherche des Mines de
Fer a l'aide de Mesures magnetiques_ (Soc. Royale des Sciences d'Upsal,
1877); or B. R. Brough, _The Use of the Magnetic Needle in exploring for
Iron Ore_ (_Scientific American_, Suppl. No. 608, p. 9708, Aug. 27, 1887).

Quite recently Dr. Henry Wilde, F.R.S., has endeavoured to elucidate the
deviations of the compass as the result of the configurations of land and
sea on the globe, by means of a model globe in which the ocean areas are
covered with thin sheet iron. This apparatus Dr. Wilde calls a
_Magnetarium_. See _Proc. Roy. Soc._, June, 1890, Jan., 1891, and June,
1891. {16} An actual magnetic rock exists in Scandinavia, t