certaining and
providing for the correction of the heeling error with the ship
upright continue to be of great value to safe navigation. In 1855 the
Liverpool Compass Committee began its work of investigating the
magnetism of ships of the mercantile marine, resulting in three
reports to the Board of Trade, all of great value, the last being
presented in 1861.

See also MAGNETISM, and NAVIGATION; articles on Magnetism of Ships and
Deviations of the Compass, _Phil. Trans._, 1839-1883, _Journal United
Service Inst._, 1859-1889, _Trans. Inst. Nav. Archit._,
1860-1861-1862, _Report of Brit. Assoc._, 1862, _London Quarterly
Rev._, 1865; also _Admiralty Manual_, edit. 1862-1863-1869-1893-1900;
and Towson's _Practical Information on Deviations of the Compass_
(1886). (E. W. C.)

_History of the Mariner's Compass._

The discovery that a lodestone, or a piece of iron which has been
touched by a lodestone, will direct itself to point in a north and south
position, and the application of that discovery to direct the navigation
of ships, have been attributed to various origins. The Chinese, the
Arabs, the Greeks, the Etruscans, the Finns and the Italians have all
been claimed as originators of the compass. There is now little doubt
that the claim formerly advanced in favour of the Chinese is
ill-founded. In Chinese history we are told how, in the sixty-fourth
year of the reign of Hwang-ti (2634 B.C.), the emperor Hiuan-yuan, or
Hwang-ti, attacked one Tchi-yeou, on the plains of Tchou-lou, and
finding his army embarrassed by a thick fog raised by the enemy,
constructed a chariot (Tchi-nan) for indicating the south, so as to
distinguish the four cardinal points, and was thus enabled to pursue
Tchi-yeou, and take him prisoner. (Julius Klaproth, _Lettre a M. le
Baron Humboldt sur l'invention de la boussole_, Paris, 1834. See also
Mailla, _Histoire generale de la Chine_, tom. i. p. 316, Paris, 1777.)
But, as other versions of the story show, this account is purely
mythical. For the south-pointing chariots are recorded to have been
first devised by the emperor Hian-tsoung (A.D. 806-820); and there is no
evidence that they contained any magnet. There is no genuine record of a
Chinese marine compass before A.D. 1297, as Klaproth admits. No
sea-going ships were built in China before 139 B.C. The earliest
allusion to the power of the lodestone in Chinese literature occurs in a
Chinese dictionary, finished i