ntry long remained unknown to Europeans. Gustav
Nachtigal spent some time in it in the year 1871, and gave a valuable
account of the region and its inhabitants in his book, _Sahara und
Sudan_ (Berlin, 1879-1889). In 1899 Borku, by agreement with Great
Britain, was assigned to the French sphere of influence. The country,
which had formerly been periodically raided by the Walad Sliman Arabs,
was then governed by the Senussi (q.v.), who had placed garrisons in the
chief centres of population. From it raids were made on French
territory. In 1907 a French column from Kanem entered Borku, but after
capturing Ain Galakka, the principal Senussi station, retired. Borku is
also called Borgu, but must not be confounded with the Borgu (q.v.) west
of the Niger.

A summary of Nachtigal's writing on Borku will be found in section 28
of _Gustav Nachtigal's Reisen in der Sahara und im Sudan_ (1 vol.),
arranged by Albert Frankel (Leipzig, 1887). See also an article (with
map) by Commdt. Bordeaux in _La Geographie_, Oct. 1908.

BORKUM, an island of Germany, in the North Sea, belonging to the
Prussian province of Hanover, the westernmost of the East Frisian chain,
lying between the east and west arms of the estuary of the Ems, and
opposite to the Dollart. Pop. about 2500. The island is 5 m. long and
2-1/2 m. broad, is a favourite summer resort, and is visited annually by
about 20,000 persons. There is a daily steamboat service with Emden,
Leer and Hamburg during the summer months. The island affords pasture
for cattle, and a breeding-place for sea-birds.

BORLASE, WILLIAM (1695-1772), English antiquary and naturalist, was born
at Pendeen in Cornwall, of an ancient family, on the 2nd of February
1695. He was educated at Exeter College, Oxford, and in 1719 was
ordained. In 1722 he was presented to the rectory of Ludgvan, and in
1732 he obtained in addition the vicarage of St Just, his native parish.
In the parish of Ludgvan were rich copper works, abounding with mineral
and metallic fossils, of which he made a collection, and thus was led to
study somewhat minutely the natural history of the county. In 1750 he
was admitted a fellow of the Royal Society; and in 1754 he published, at
Oxford, his _Antiquities of Cornwall_ (2nd ed., London, 1769). His next
publication was _Observations on the Ancient and Present State of the
Islands of Scilly, and their Importance to the Trade of Great Britain_
(Oxford, 1756). In 1758 appea