The _Fal_, which is the most considerable river in the centre of the county, rises about two miles west of Roche Rocks, and after a course of 12 miles, meets the tide below Tregony, and passing Tregothnan Park, joins Truro and St. Clement’s Creeks, which are navigable to Truro Quay and Tresilian Bridge; from its junction with those creeks, after flowing four or five miles, it forms the principal branches of Falmouth Harbour, named Carrick and King’s Road. The river _Alan_ or _Camel_, rises on the north-east side of the county, near Camelford, and after a circuitous course of 12 miles, becomes navigable for barges at Egleshale, near Wadebridge, from whence it flows into the harbour of Padstow. On all these rivers, as well as others of less note, great quantities of sea sand are carried in barges for manure, and sold to the farmers at a very reasonable rate. The most considerable _lake_ in Cornwall, is the _Loo Pool_, near Helston, and which is about two miles long and a furlong wide, formed of a bar of pebbles, sand, and shingles, forced up against the mouth of the creek, by the south-west winds; but in the winter time, the whole valley between the sea and Helston, is frequently covered with water. _Dosmery Pool_, is a piece of water about a mile in circumference, lying in the parish of Alternon, on the borders of St. Cleer parish, and said by _Leland_, to be 15 fathoms deep, but which, upon trial, a few years back, was found to be only nine feet. It is formed and supplied by water which drains from the neighbouring hills. Between Budock and Falmouth is a piece of water, near half a mile in length, and secured from the sea, by a bar of sand and shingles, called _Swan Pool_, from the circumstance of its having had many swans kept on it some years ago. The _Soils_ of Cornwall chiefly consist of three species: first, the _black growan_ or _gravelly_; second, the _shelfy_ or _slaty_; third, loams differing in texture, colours, and degrees of fertility.