boring a tunnel over 1/2 m. in length, now called Grotta della Pace,
through the hill on the north-west side of Lake Avernus. After Sextus
Pompeius had been subdued, the chief naval harbour was transferred to
Misenum. Nero's works for his proposed canal from Baiae to the Tiber (A.D.
64) seem to have begun near Lake Avernus; indeed, according to one theory,
the Grotta della Pace would be a portion of this canal. On the east side of
the lake are remains of baths, including a great octagonal hall known as
the Temple of Apollo, built of brickwork, and belonging to the 1st century.
The so-called Grotto of the Cumaean Sibyl, on the south side, is a rock-cut
passage, ventilated by vertical apertures, possibly a part of the works
connected with the naval harbour. To the south-east of the lake is the
Monte Nuovo, a volcanic hill upheaved in 1538, with a deep extinct crater
in the centre. To the south is the Lacus Lucrinus.

See J. Beloch, _Campanien_ (2nd ed., Breslau, 1890), pp. 168 seq.

(T. AS.)

AVERROES [Ab[=u]l-Wal[=i]d Mu[h.]ammad ibn-A[h.]mad Ibn-Mu[h.]ammad
ibn-Rushd] (1126-1198), Arabian philosopher, was born at Cordova. His early
life was occupied in mastering the curriculum of theology, jurisprudence,
mathematics, medicine and philosophy, under the approved teachers of the
time. The years of his prime fell during the last period of Mahommedan rule
in Spain under the Almohades (_q.v._). It was Ibn-Tufail (Abubacer), the
philosophic vizier of Yusef, who introduced Averroes to that prince, and
Avenzoar (Ibn-Zuhr), the greatest of Moslem physicians, was his friend.
Averroes, who was versed in the Malekite system of law, was made cadi of
Seville (1169), and in similar appointments the next twenty-five years of
his life were passed. We find him at different periods in Seville, Cordova
and Morocco, probably as physician to Yusef al-Mansur, who took pleasure in
engaging him in discussions on the theories of philosophy and their
bearings on the faith of Islam. But science and free thought then, as now,
in Islam, depended almost solely on the tastes of the wealthy and the
favour of the monarch. The ignorant fanaticism of the multitude viewed
speculative studies with deep dislike and distrust, and deemed any one a
Zendik (infidel) who did not rest content with the natural science of the
Koran. These smouldering hatreds burst into open flame about the year 1195.
Averroes was accused of heretical opinions and pursuits, stripped