which no other master has equalled. He
frequently painted by the aid of a concave mirror, and to obtain
exactness looked at his subject through a frame crossed with squares of
silk thread. His practice as a portrait painter, which was at first
considerable, gradually declined, sitters being unwilling to give him
the time that he deemed necessary. His pictures were always small in
size, and represented chiefly subjects in still life. Upwards of 200 are
attributed to him, and specimens are to be found in most of the great
public collections of Europe. His _chef-d'oeuvre_ is generally
considered to be the "Woman sick of the Dropsy," in the Louvre. The
"Evening School," in the Amsterdam gallery, is the best example of the
candlelight scenes in which he excelled. In the National Gallery,
London, favourable specimens are to be seen in the "Poulterer's Shop,"
and a portrait of himself. Douw's pictures brought high prices, and it
is said that President Van Spiring of the Hague paid him 1000 florins a
year simply for the right of pre-emption. Douw died in 1680. His most
celebrated pupil was Francis Mieris.

DOVE, a river of England, tributary to the Trent, rising in Axe Edge,
Derbyshire, and through almost its entire course forming the boundary of
that county with Staffordshire. In its upper course it traverses a fine
narrow valley, where the limestone hills exhibit many picturesque
cliffs, gullies and caves. Dovedale, that part of the valley which lies
between Dove Holes and Thorpe Cloud (or with a wider significance
between the towns of Hartington and Ashbourne), is especially famous.
Below Thorpe Cloud the Dove receives on the west the waters of the
Manifold, which, like its tributary the Hamps, and other streams in the
limestone district, has part of its course below ground. Near the
village of Rocester the Churnet joins the Dove on the west, and then the
course of the main stream, hitherto southerly, bends nearly easterly on
passing Uttoxeter, and, winding through a widening valley, joins the
Trent at Newton Solney, a short distance below Burton-on-Trent. The
length of the valley is about 40 m. and the total fall of the river
about 1450 ft. The Dove is well known for its trout-fishing, and the
portion of the upper valley called Beresford Dale, below Hartington, has
a special interest for fishermen through its associations with Izaak
Walton and his friend Charles Cotton, whose fishing-house stands near
the Pike Pool, a