Cornwall, being so surrounded by the sea, and so peculiarly under the influence of the Gulf Stream, may be looked upon as possessing a local "insular" climate in a marked degree. The south-west wind almost invariably brings rain and warmth together, for the high cold granitic moorlands are naturally calculated to arrest these warm airs and chill them, causing thereby a downfall of the suspended water. But Cornwall does not enjoy the amount of sun heat to ripen fruit that is obtained on the east coast of England, and it is exposed to furious gales from the west. "The gale from the west," says Polwhele, "is here no gentle zephyr; instead of wafting perfume on its wings, it often brings devastation." On the north coast every tree that is exposed to it is dwarfed and bowed like a curling wave, and the foliage in spring is often cut and browned by the salt spray. Even tombstones in the churchyards on the heights have to be backed up with masonry, and the churches are low, as if cowering from the blast. According to a Cornish proverb: "There falls a shower on every week day, and there are two on a Sunday." In Scilly, however, there is more sunshine and less rain than on the mainland. The myrtle, geranium, fuchsia, and hydrangea grow luxuriantly; the red geranium at Penzance will cover the front of a house, and palms and other exotics thrive there and at Falmouth. The fields of narcissus and daffodils cultivated for the market would be more beautiful if the blooms were not systematically picked before fully open, to be sent to London. No gardens in England exhibit such a wealth of exotics as those of Tresco, Carclew, Enys and Penjerrick, and some others in the district of the Fal estuary, which seems peculiarly favourable for the growth of sub-tropical species.
In 1906, the mean temperature of England and Wales was 49·3° Fahr., while that of Cornwall was 51·2. The mean temperature of England in 1907 was 48·5, of Cornwall 50·6. But there exists a considerable difference between north and south. At Redruth it was in 1906, 50·1, whereas at Truro it was nine degrees higher.
The east wind prevails in October and is strong in March, the south-east in June, the south-west is felt in every month save April, but very little in December. The west wind is most prevalent in August, least so in May. The north wind predominates in December and July.
The rainfall chart here given shows that Cornwall lies for the most part in an area where from 40 to 60 inches are annually recorded, though a strip of the north coast from St Ives to Padstow and again from Boscastle to the northern limit of the county shows a fall of less than 40 inches. This is because the uplands have robbed the rainclouds of a considerable portion of their contents, and accordingly it is on these high moorlands that we find the greatest rainfall. Thus on the moors between Launceston and Bodmin from 60 to 80 inches fall, and even this latter figure is exceeded in the neighbourhood of Rough Tor and Brown Willy.
From observations taken at the Royal Institution of Cornwall at Truro, from 1850 to 1881 it appears that the rainiest months are November and December, and next to them January and July; April and May are the least rainy.
13. People—Race, Dialect, Population.
The original population of Cornwall would seem to have been what is now commonly called Ivernian, the same as Iberian, the underlying race everywhere in Western Europe from the western isles of Scotland to Gibraltar. When the Romans invaded and conquered Spain, they found there already in the east the Celts and in the west the Iberians, and they designated the more or less fused population, Celtiberians. So in Cornwall, there was this dark-haired, dusky-skinned race, and the Brythons, Celts, of the people of the Dumnonii. There were extensive settlements by Irish in the Land's End district, the Lizard, and along the north coast, in 490-510, owing to the expulsion of the Ossorians and the Bairrche from their lands in Ireland. The Saxon also crossed the Tamar and peaceably settled in East Cornwall.
The language spoken was Brythonic, akin to, and originally identical with Welsh and that spoken in Lower Brittany. It was distinct in some points from the Goidelic of Ireland, the Isle of Man, and the Highlands of Scotland. The main difference was that the C in the latter became P in the former. Thus Ken or Cen in such names as Kenmare and Ciaran would in Cornish become Penmare and Piran.
In the reign of Edward I, Cornish was spoken in the south Hams of Devonshire, but in the sixteenth century it was dying out even in West Cornwall. Norden, writing in 1580, says: "Of late the Cornish men have much conformed themselves to the use of the English tongue, and their English is equal to the beste, especially in the eastern partes.... In the weste parte of the countrye, in the hundreds of Penwith and Kirrier, the Cornishe tongue is most in use amongste the inhabitants." At Menheniot about 1540 the Creed and the Lord's Prayer were first taught the people in English. In 1678, at Landewednack, the last Cornish sermon on record was preached. In the reign of George III (1777) died Dolly Pentreath, the last to speak the language.