Dartmoor, a large moorland and forest tract of West Devonshire. The forest rights belong to the Duchy of Cornwall. The only timber the moor produces is dwarf oak, ash, and willow. Extending 20 miles from N. to S., with a breadth of 20 miles, and an area of about 150,000 acres, the surface is mountainous and rugged, and abounds in tors, of which Yes Tor has a height of 2,050 feet. In swamps on the moor the rivers Dart, Teign, and Taw, as well as others, take their rise. A prison, which was built for French prisoners in the early part of the present century, has since been turned into a convict prison, and is surrounded by a district which has been brought into cultivation. The settlement of over 30 acres takes its name from the adjoining village of Princetown. In summer cattle and sheep are pastured on the moor, but in winter it is a stormy, forlorn, and desolate region. Tin, copper, and iron have been worked, and gold has been found in the rivers. Attempts, too, have been made to utilise the peat, which is plentiful, but little success has attended them. The chief product is china-clay. It is a bleak bare upland moor of heather and peat-bog rising into numerous summits capped by piles of remarkable detached and disintegrated granite blocks known as "tors." Some of these blocks have been hollowed into "rock-basins" by weathering. The moor is rich in stone monuments, the maenhirs, or large upright stones, lines of stones as at Carnac in Brittany, villages of round stone huts, pounds, or enclosures, with stone walls, and "clam" or slab bridges being pre-historic; whilst numerous granite crosses belong to a more modern date. Dartmoor has been a royal forest from early times.