[B] An estuary is a sort of bay, produced by the widening of a river at
its mouth. Scotland is remarkable for the estuaries which are formed at
the mouths of its rivers. They are called there _friths_.

The Forth and the Clyde, with their estuaries, almost cut Scotland in
two; and by means of them ships and steamers from all parts of England
and from foreign ports are enabled to come into the very heart of the
country.

The two largest and most celebrated cities in Scotland are situated in
the valleys of these rivers, the Forth and the Clyde. They are
Edinburgh and Glasgow. Edinburgh is on the Forth, though situated at
some little distance from its banks. Glasgow is on the Clyde. There is a
railway extending across from Edinburgh to Glasgow, and also a canal,
connecting the waters of the Forth with the Clyde. The region of these
cities, and of the canal and railroad which connects them, is altogether
the busiest, the most densely peopled, and the most important portion of
Scotland; and this is the reason why Mr. George wished to come directly
into it by water from Liverpool.

The cities of Glasgow and Edinburgh, though both greatly celebrated, are
celebrated in very different ways. Edinburgh is the city of science, of
literature, and of the arts. Here are many learned institutions, the
fame and influence of which extend to every part of the world. Here are
great book publishing establishments, which send forth millions of
volumes every year--from ponderous encyclopaedias of science, and
elegantly illustrated and costly works of art, down to tracts for
Sabbath schools, and picture books for children. The situation of
Edinburgh is very romantic and beautiful; the town being built among
hills and ravines of the most picturesque and striking character. When
Scotland was an independent kingdom Edinburgh was the capital of it,
and thus the old palace of the kings and the royal castle are there, and
the town has been the scene of some of the most remarkable events in the
Scottish history.

Glasgow, on the other hand, which is on the Clyde, towards the western
side of the island, together with all the country for many miles around
it, forms the scene of the mechanical and manufacturing industry of
Scotland. The whole district, in fact, is one vast workshop; being full
of mines, mills, forges, furnaces, machine shops, ship yards and iron
works, with pipes every where puffing out steam, and tall chimneys,
higher, some of