Page:EB1911 - Volume 07.djvu/197

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180
CORNWALL

the Helford river. On the north are the estuaries of the Camel and the Hayle, debouching into Padstow Bay and St Ives Bay respectively. The Fowey and Camel valleys almost completely break the continuation of the central high ground, and the uplands west of Mount’s Bay are similarly parted from the main mass by the low tract between Hayle and Marazion. Except at the mouth of a stream or estuary the coast is almost wholly rock-bound, and the cliff scenery is unsurpassed in England. Three different types are found. On the north coast, from Tintagel Head and Boscastle northward to Hartland Point in Devonshire, the dark slate cliffs, with their narrow and distorted strata, are remarkably rugged of outline, owing to the ease with which the waves fret the loosely-bound rock. On the south, in the beautiful little bays in the neighbourhood of the Lizard Point, the serpentine rock is noted for its exquisite colouring. Between Treryn and Land’s End, at the south-west, a majestic barrier of granite is presented to the sea. The beautiful Scilly Isles continue the line of the granite, and the intervening sea is said to have submerged a tract of land named Lyonesse, containing, according to tradition, 140 parish churches, and intimately connected with the Arthurian romances.

Geology.—One of the most striking features of Cornwall is the presence of the four great masses of granite which rise up and form as many elevated areas out of a lower-lying region occupied by rocks almost entirely slaty in character, generally known as “Killas.” The granite is not the oldest of the Cornish rocks; these are found in the Lizard peninsula and are represented by serpentine, gabbro and metamorphic schists. With the exception of a small tract about Veryan and Gorran, of Ordovician age, all the sedimentary rocks, as far as a line joining Boscastle and South Petherwin, were formerly classed as Devonian; to the north of the line are the Culm measures—slates, grits and limestones—of Carboniferous age. The extensive spread of Killas is not, however, entirely Devonian, as it is shown on most maps. In the northern portion, Lower, Middle and Upper Devonian can be distinguished; the lower beds at Polperro, Looe and Watergate, the higher beds along the line indicated above. Farther south it has been shown that an older set of Palaeozoic rocks constitutes at least a part of the Killas; the Veryan series, with Caradoc fossils, is succeeded in descending order by the Portscatho series, the Falmouth series and the Mylor series; the lowest Devonian beds represented here by the Menaccan series, rest unconformably upon these Ordovician beds. Upper Silurian fossils have been found near Veryan. All these rocks have been subjected to severe thrusting from the south, consequently they are much contorted and folded. After this thrusting and folding had taken place, intrusions of diabase, &c., penetrated the sedimentary strata in numerous places, but it was not until post-Carboniferous times that the granite masses were intruded. The principal granite masses are those of St Just and Land’s End, Penryn, St Austell and Bodmin Moor. To the granite Cornwall owes much of its prosperity; it has altered the Killas for some distance around each mass, and the veins of tin and copper ore, though richest in the Killas, are evidently genetically related to the granite. The principal metalliferous districts, Camborne, Redruth, St Just, &c., all lie near the granite margins. The china clay and china stone industry is dependent on the fact that the granite was itself altered in patches during the later phases of eruptive activity by the agency of boric and fluoric vapours which kaolinized the felspar of the granite. Later eruptions produced dykes of quartz-porphyry and other varieties, all locally called “elvans,” which penetrate both the granite and the Killas. Small patches of Pliocene strata are found at St Erth and St Agnes Beacon. Blown sand is an important feature at St Pirran, Lelant, Gwythian and elsewhere, and raised beaches are frequent round the coast. A characteristic Cornish deposit is the “Head,” an old consolidated scree or talus. Many rare minerals have been obtained from the mines and much tin ore has been taken from the river gravels. The river gravel at Carnon has yielded native gold.

Climate.—The climate of Cornwall is peculiar. Snow seldom lies for more than a few days, and the winters are less severe than in any other part of England, the average temperature for January being 34° F. at Bude and 43.7° at Falmouth. The sea-winds, except in a few sheltered places, prevent timber trees from attaining to any great size, but the air is mild, and the lower vegetation, especially in the Penzance district, is almost southern in its luxuriance. Geraniums, fuchsias, myrtles, hydrangeas and camellias grow to a considerable size, and flourish through the winter at Penzance and round Falmouth; and in the Scilly Isles a great variety of exotics may be seen flourishing in the open air. Stone fruit, and even apples and pears, do not attain the same full flavour as in the neighbouring county, owing to the want of dry heat. The pinaster, the Pinus austriaca, Pinus insignis and other firs succeed well in the western part of the county. All native plants display a perfection of beauty hardly to be seen elsewhere, and the furze, including the double-blossomed variety, and the heaths, among which Erica vagans and ciliaris are characteristic, cover the moorland and the cliff summits with a blaze of the richest colour. On the whole the climate is healthy, though the prevalent westerly and south-westerly winds, bringing with them great bodies of cloud from the Atlantic, render it damp; the mean annual rainfall, though only 32.85 in. at Bude, reaches 44.41 at Falmouth, and 50.57 at Bodmin.

Agriculture.—About seven-tenths of the total area is under cultivation, but oats form the only important grain-crop. Turnips, swedes and mangolds make up the bulk of the green crops. The number of cattle (chiefly of the Devonshire breed) is large, and many sheep are kept; nearly 60,000 acres of hill pasture being recorded. As regards agricultural produce, however, Cornwall is chiefly famous for the market-gardening carried on in the neighbourhood of Penzance, where the climate is specially suitable for the growth of early potatoes, broccoli and asparagus. These are despatched in large quantities to the London market; the Scilly Isles sharing in the industry. Fruit and flowers are also grown for the market. In the valleys the soil is frequently rich and deep; there are good arable and pasture farms, and the natural oak-wood of these coombes has been preserved and increased by plantation.

Mining.—The wealth of Cornwall, however, lies not so much in the soil, as underground and in the surrounding seas. Hence the favourite Cornish toast, “fish, tin and copper.” The tin of Cornwall has been known and worked from a period anterior to certain history. There is no direct proof that the Phoenician traders came to Cornwall for tin; though it has been sought to identify the Cassiterides (q.v.) or Tin Islands with the county or the Scilly Isles. By ancient charters the “tinners” were exempt from all jurisdiction (save in cases affecting land, life and limb) other than that of the Stannary Courts, and peculiar laws were enacted in the Stannary parliaments (see Stannaries). For many centuries a tax on the tin, after smelting, was paid to the earls and dukes of Cornwall. The smelted blocks were carried to certain towns to be coined, that is, stamped with the duchy seal before they could be sold. By an act of 1838 the dues payable on the coinage of tin were abolished, and a compensation was awarded to the duchy instead of them. The Cornish miners are an intelligent and independent body, and the assistance of a Cornishman has been found necessary to the successful development of mining in many parts of the world, while many miners have emigrated from Cornwall to more remunerative fields abroad. The industry has suffered from periods of depression, as before the accession of Queen Elizabeth, who introduced miners from Germany to resuscitate it; and in modern times the shallow workings, from which tin could be easily “streamed,” have become practically exhausted. The deeper workings to which the miners must needs have recourse naturally render production more costly, and the competition of foreign mines has been detrimental. The result is that the industry is comparatively less prosperous than formerly, and employs far fewer of the inhabitants. However, in the district of Camborne, Carn Brea, Illogan and Redruth, and near St Just in the extreme west, the mines are still active, while there are others of less importance elsewhere, as near Callington in the south-east. And when, as in 1906, circumstances affecting the production of foreign mines cause a rise in the price of tin, the Cornish mines enjoy a period of greater prosperity; the result being the recent reopening of many of the mines which had been closed for twenty years. The largest tin-mine is that of Dolcoath near Camborne. Copper is extracted at St Just and at Carn Brea; but the output has decreased much further than that of tin. As it lies deeper in the earth, and consequently could not be “streamed” for, it was almost unnoticed in the county until the end of the 15th century, and little attention was paid to it until the last years of the 17th. No mine seems to have been worked exclusively for copper before the year 1770; and up to that time the casual produce had been