d Keighley, remain, but
most of them have developed by manufactures into great centres of
population, lying, as a rule, at the junction of thickly peopled
valleys, and separated from one another by the empty uplands. Such are
Leeds, Bradford, Sheffield, Huddersfield and Halifax on the great and
densely peopled West Riding coal-field, which lies on the eastern
slope of the Pennines. The iron ores of the Coal Measures have given
rise to great manufactures of steel, from cutlery to machinery and
armour-plates. High on the barren crest of the Pennines, where the
rocks yield no mineral wealth, except it be medicinal waters,
Harrogate, Buxton and Matlock are types of health resorts, prosperous
from their pure air and fine scenery. Across the moors, on the western
side of the anticline, the vast and dense population of the Lancashire
coal-field is crowded in the manufacturing towns surrounding the great
commercial centre, Manchester, which itself stands on the edge of the
Triassic plain. Ashton, Oldham, Rochdale, Bury, Bolton and Wigan form
a nearly confluent semicircle of great towns, their prosperity founded
on the underlying coal and iron, maintained by imported cotton. The
Lancashire coal-field, and the portion of the bounding plain between
it and the seaport of Liverpool, contain a population greater than
that borne by any equal area in the country, the county of London and
its surroundings not excepted. In the south-west of the Pennine region
the coal-field of North Staffordshire supports the group of small but
active towns known collectively from the staple of their trade as "The
Potteries." On the north-east the great coal-field of Northumberland
and Durham, traversed midway by the Tyne, supports the manufactures of
Newcastle and its satellite towns, and leaves a great surplus for
export from the Tyne ports.

_Wales._--The low island of Anglesey, which is built up of the
fundamental Archaean rocks, is important as a link in the main line of
communication with Ireland, because it is separated from the mainland
by a channel narrow enough to be bridged, and lies not far out of the
straight line joining London and Dublin. The mainland of Wales rises
into three main highlands, the mountain groups of North, Mid and South
Wales, connected together by land over 1000 ft. in elevation in most
places, but separated by valleys affording easy highways. The streams