a_ of Tacitus),
the principal river of Lanarkshire, Scotland. It is also the name of the
estuary which forms the largest and finest firth on the west coast.

1. _The River._--Daer Water, rising in Gana Hill (2190 ft.) on the
borders of Lanarkshire and Dumfriesshire, after a course of 10-1/2 m., and
Potrail Water, rising 3 m. farther W. in the same hilly country (1928
ft.), after running N.N.E. for 7 m., unite 3-1/2 m. S. of Elvanfoot to form
the Clyde, of which they are the principal headstreams, though many
mountain burns in these upland regions are also contributory. The old
rhyme that "Annan, Tweed and Clyde rise a' out o' ae hillside" is not
true, for Little Clyde Burn here referred to, rising in Clyde Law (2190
ft.), is only an affluent and not a parent stream. From the junction of
the Daer and Potrail the river pursues a direction mainly northwards for
several miles, winding eastwards around Tinto Hill, somewhat
north-westerly to near Carstairs, where it follows a serpentine course
westwards and then southwards. From Harperfield, a point about 4 m.
above Lanark, it assumes a north-westerly direction, which, roughly, it
maintains for the rest of its course as a river, which is generally held
to end at Dumbarton, where it merges in the Firth. Its principal
tributaries on the right are the Medwin (16 m. long), entering near
Carnwath, the Mouse (15 m.), joining it at Lanark, the South Calder (16
m.) above Bothwell, the North Calder (12 m.) below Uddingston, the
Kelvin (21 m.) at Glasgow, and the Leven (7 m.) at Dumbarton. The chief
left-hand affluents are the Elvan (8 m.), entering at Elvanfoot, the
Duneaton (19 m.), joining a few miles above Roberton, the Garf (6-1/2 m.)
below Lamington, the Douglas (20 m.) above Bonnington, the Nethan (12
m.) at Crossford, the Avon (28 m.) at Hamilton, the Rotten Calder (10
m.) near Newton, and the Cart (1 m.), formed by the junction of the
Black Cart (9 m.) and the White Cart (19 m.), below Renfrew.

The total length of the Clyde from the head of the Daer to Dumbarton is
106 m., and it drains an area estimated at 1481 sq. m. It is thus the
third longest river in Scotland (being exceeded by the Spey and Tay),
but in respect of the industries on its lower banks, and its sea-borne
commerce, it is one of the most important rivers in the world. Near
Lanark it is broken by the celebrated Falls, four in number, which are
all found within a distance of 3-3/4 m. Bonnington Linn, the most gr