centres of French
textiles, especially woollen goods; is strongly fortified.

RHEINGAU, a fruitful wine district in the Rhine Valley, stretching
along the right bank of the river in Hesse-Nassau; has a sunny, sheltered
situation, and its wines are famed for their quality.

RHENISH PRUSSIA (4,710), the most westerly and most densely
populated of the Prussian provinces, lies within the valleys of the Rhine
and the Lower Moselle, and borders on Belgium and the Netherlands; is
mountainous and forest-clad, except in the fertile plains of the N. and
in the rich river valleys, where vines, cereals, and vegetables are
extensively cultivated; large quantities of coal, iron, zinc, and lead
are mined; as an industrial and manufacturing province it ranks first in
Germany. Coblenz (capital), Aix-la-Chapelle, Bonn, and Cologne are among
its chief towns; was formed in 1815 out of several smaller duchies.

RHEOCHORD, a wire to measure the resistance or variability of an
electric current.

RHEOMETRY, measurement of the force or the velocity of an electric
current.

RHESUS, a monkey held sacred in several parts of India.

RHETORIC, the science or art of persuasive or effective speech,
written as well as spoken, and that both in theory and practice was
cultivated to great perfection among the ancient Greeks and Romans, and
to some extent in the Middle Ages and later, but is much less cultivated
either as a science or an art to-day.

RHINE, one of the chief rivers of Europe; of several small Alpine
head-streams, the Nearer and the Farther Rhine are the two principal,
issuing from the eastern flanks of Mount St Gothard; a junction is formed
at Reichenau, whence the united stream--the Upper Rhine--flows N. to Lake
Constance, and issuing from the NW. corner curves westward to Basel,
forming the boundary between Switzerland and Germany. From Basel, as the
Middle Rhine, it pursues a northerly course to Mainz, turns sharply to
the W. as far as Bingen, and again resumes its northward course. The
Rhine-Highland between Bingen and Bonn is the most romantic and
picturesque part of its course. As the Lower Rhine it flows in a
sluggish, winding stream through the Rhenish Lowlands, enters Holland
near Cleves, at Nimeguen bends to the W., and flowing through Holland
some 100 m. reaches the German Ocean, splitting in its lowest part into
several streams which form a rich delta, one-third of Holland. It is 800
m. in length; receives