of Ottawa) in Ontario, but this material was later shown on
microscopical examination to be a mixture. The name was afterwards applied
by G. Tschermak to those plagioclase felspars which lie between labradorite
and anorthite; and this has been generally adopted by petrologists. In
chemical composition and in optical and other physical characters it is
thus much nearer to the anorthite end of the series than to albite. Like
labradorite and anorthite, it is a common constituent of basic igneous
rocks, such as gabbro and basalt. Isolated crystals of bytownite bounded by
well-defined faces are unknown.

(L. J. S.)

BYWATER, INGRAM (1840- ), English classical scholar, was born in London on
the 27th of June 1840. He was educated at University and King's College
schools, and at Queen's College, Oxford. He obtained a first class in
Moderations (1860) and in the final classical schools (1862), and became
fellow of Exeter (1863), reader in Greek (1883), regius professor of Greek
(1893-1908), and student of Christ Church. He received honorary degrees
from various universities, and was elected corresponding member of the
Prussian Academy of Sciences. He is chiefly known for his editions of Greek
philosophical works: _Heracliti Ephesii Reliquiae_ (1877); _Prisciani Lydi
quae extant_ (edited for the Berlin Academy in the _Supplementum
Aristolelicum_, 1886); Aristotle, _Ethica Nicomachea_ (1890), _De Arte
Poetica_ (1898); _Contributions to the Textual Criticism of the Nicomachean
Ethics_ (1892).

BYZANTINE ART

PLATE I.

[Illustration: INTERIOR OF THE HOLY WISDOM (S. SOPHIA), CONSTANTINOPLE.
Sixth century, the dome was rebuilt in the tenth century. The metal
balustrades, pulpits, and the large discs are Turkish.]

CAPITALS OF COLUMNS.

[Illustration: S. VITALI, RAVENNA.
Sixth century.]

[Illustration: S. MARK, VENICE.
Eleventh century.]

[Illustration: S. APOLLINARI, RAVENNA.
Sixth century.]

PLATE II.

[Illustration: SMALL MEDIEVAL CATHEDRAL, ATHENS. _Photo: Emery Walker._]

[Illustration: INTERIOR OF ST. LUKE'S, NEAR DELPHI.

Showing a typical scheme of internal decoration. The lower parts of the
walls are covered with marble, and the upper surfaces and vaults with
mosaics and paintings. Eleventh century. _From a Drawing by Sidney
Barnsley._]

BYZANTINE ART.[1] By "Byzantine art" is meant the art of Constantinople
(sometimes called _Byzantium_ in the middle ages as in antiquity), and of
the Byzantine empire; it