There seems to be little doubt that the climate of Scotland was considerably milder in ancient times than it is at present; and indeed this appears to be true of all the western kingdoms of Europe. When Julius CRsar landed in England on the 29th of Au gust, according to Dr. Halley, he found that all the corns were reaped except in one district. Ctrsar states that the climate of Britain was more temperate, and the cold less severe than in Gaul; and we read in Tacitus, that the sky was foul with continued rains and fogs, but that it was free from the rigours of cold. It is related by Flavius Vopiscus, in his Life of Probus, that the emperor gave permission to the Britains to raise vines and to manufacture wine; and Beda informs us that vineyards were cultivated in Britain.
It appears from the records of religious houses, that in the parish of Lesmahago in Lanarkshire, wheat was formerly paid as tyfhe from lands, whereas for several centuries hack, its climate is scarcely fit for bringing oats to perfection. In the parish of Glen luce too, in Wigtonshire, 12 bolls of wheat and 12 bolls of barley were formerly paid in tythe by a farm, which, about 40 years ago, brought a rent of only L. 12.
An argument in favour of the deterioration of our climate, by no means devoid or plausibility, has been drawn from the inferior size of the wild animals that are now produced, and also of our vegetable produc tions; but as this is controversial ground, we shall not enter upon it any farther.
Mr. Aiton has ascribed the deterioration of the cli mate of Scotland to the immense accumulations of moss earth which have arisen from the demolition of forests since the invasion of the Romans. " Moss earth is peculiar to countries situated in a high lati tude. It is produced by the accumulation of vegetable substances in a decayed and waste state. The bulk is increased gradually by the addition of vegetables of the mossy tribes which grow upon its surface. Of all other soils, peat earth absorbs and retains the greatest quantity of water; 321 oz. of dry moss soil, will retain without fluidity 18 oz. of water; whilst 39 oz. of the richest garden mould will only retain 181 oz. Moss is also more retentive of cold than any other soil; frost is often found to continue in deep mosses till after the middle of summer. Hence the effects of mossy accumulations, in rendering the climate colder. The cold evaporations which arise from such immense tracts of the soil as exist, particularly in Scotland, chill the atmosphere, and increase the bleakness of the climate."* In treating of the climate of Scotland, Dr. Graham of Aberfoyle, whose judicious selections from the Statistical Account we shall here make use of, divides it into three districts; 1. The west coast of Scotland
from the south; 2. The middle zone, including the midland counties; and 3. The eastern coast of Scot land.
1. Climate of the Trest Coast.
The counties of Kirkcudbright and Wigton, on the south-west coast, enjoy a pure and salubrious air. The lower parts in particular have less rain than the more northern districts of the west coast, an effect which is probably produced by the shelter which it receives from Ireland. In the interior of Kirkcud brightshire the frosts are sometimes intense, but the snow does not lie long. In Wigtonshire, the winters are very cold, and the air though moist is salubrious.
Ayrshire has a mild and temperate climate, but the air is very moist and damp. The westerly winds blow severely on the coast during the winter.
Renfrewshire is visited with frequent and heavy rains, and in Dumbartonshire, which has the same character, the rains which conic from the south and south-east arc accompanied with high winds.
Argyllshire is considered the most rainy county in Scotland, being exposed to the unbroken influence of the Atlantic. The vapours of the ocean are attracted by its lofty mountains, and the clouds discharge them selves in torrents on the valleys. In the district of Cowal, and probably over the whole county, " the face of the heavens is generally louring and cloudy; a se rene sky is seldom to be seen. The winds, prevented from a free circulation, rush through the glens with irresistible violence; and, at the bottom of high bills, and in narrow valleys, the transitions from heat to cold arc sudden and excessive." The winters are, for the most part, mild and temperate; but the summers are frequently rainy and cold. Frosts are not intense, nor do snows lie long.
Inverness-shire may perhaps be considered as in some parts sheltered by the lofty mountains of Skye, and by the Western Isles, which furnish a barrier against the ocean. In its eastern districts, " the air is dry and healthy." On the west coast, as might be expected, '• the air is moist, and generally very cold; but so purified by storms, and kept in motion by rapid currents, that it is; upon the whole, clear and healthy." In the island of Skye," from the height of the hills, and the proximity of the sea, the air seldom continues long of the same temperature; sometimes it is dry, oftener moist, and in the latter end of winter and be ginning of spring, cold and piercing." The climate of the Western Isles is so stormy on the side that is exposed to the Atlantic, that the inhabitants chiefly reside on the eastern side, which is sheltered by the mountains.