Page:Encyclopædia Britannica, Ninth Edition, v. 18.djvu/696

666 PERTH of rather over 100 miles receives nearly the whole drainage of the county, discharging a larger volume of water to the sea than any other river in Great Britain ; its principal tributaries are the Tummel at Logierait, the Bran near Dunkeld, the Isla near Kinclaven (after its junction with the Ericht), the Almond near Perth, and the Earn from Loch Earn, at the borders of Fifeshire. The Forth from Loch Ard skirts the southern boundary of the county, and receives the Teith from Lochs Katrine, Achray, Yennacher, Voil, and Lubnaig, the Goodie Water from Loch Menteith, and the Allan, which rises in the Ochil Hills. Loch Ericht, partly in Inverness-shire, and Loch Tay are each more than 14 miles in length, Loch Rannoch is 9 miles long, Lochs Earn and Katrine are 7 each, and Lochs Ven- nacher, Lubnaig, and Voil each between 5 and 3. There are an immense number of small lochs varying in length from 1 to 3 miles, among which may be mentioned Garry, Tummel, Lows, Lyon, Dochart, Freuchie, Ard, and Men teith. The lochs and rivers abound in salmon and varieties of trout ; and scarcely any of the streams have been per ceptibly injured by the pollution of manufactures. About four-fifths of the surface of the county, chiefly in the west and north-west, is occupied by the Grampians, or encroached on by their ridges or by isolated summits, among the highest of the chain in Perthshire being Ben Lawers (3984 feet), north of Loch Tay; Ben More (3843) and Stobinnain (3821), south of Loch Dochart; Ben-y-Gloe (3690), and other peaks, near Glen Tilt; Schiehallion (3547), south of Loch Rannoch; and Ben Yoirlich (3180), south of Loch Earn. The Ochils, occupying a consider able area in the south-east, attain in many cases a height of over 2000 feet, and the Sidlaws, practically a con tinuation of the Ochils running into Forfarshire, reach a height of about 1 500 feet. The lowland districts consist chiefly of the straths and river-valleys, as Strathtay ; Strath- more, extending into Forfarshire; Strathearn, stretching across the county from west to east, and bounded on the south by the Ochils ; the district of Menteith between the Teith and the Forth ; and the Carse of Gowrie between the Sidlaws and the Firth of Tay. Geology and Minerals. As regards its geology Perth shire consists of two distinct areas, that differ from each other entirely in the rocks of which they are composed and consequently in their scenery. The larger of these regions comprises the mountainous ground and occupies the northern and by much the larger part of the county. The rocks in this region belong to the series of crystal line schists, and include varieties of gneiss, mica- schist, clay- slate, hornblende -rock, ifec., with important bands of quartzite, quartz -schist, and limestone. These rocks are arranged in approximately parallel folds, the axes of which range in a general sense from south-west to north east, the same groups of strata being repeated again and again by successive plications. The quartzites from their durability and whiteness form specially marked zones across the county, as in the ranges of Schiehallion and Ben-y-Gloe. The limestones also from their persistence afford excellent horizons for interpreting the geological structure. A notable band of them runs along the valley of Loch Tay, plunging under Ben Lawers and rising up again in Glen Lyon, whence it continues across Strath Tummel into Glen Tilt. These various crystalline rocks are believed to be prolongations of the schistose series that overlies the Lower Silurian rocks of Sutherland ; but they have not yet yielded fossils. They are here and there pierced by masses of granite, porphyry, or other eruptive rocks. The southern (or more correctly south-eastern) limit of the mountain ground is defined by a line drawn from the foot of Loch Lomond by Aberfoyle, Pass of Leny, Comrie, a little below Dunkeld, and Bridge of Cally, to Lintrathen. On the southern side of this line the ground presents distinctively lowland scenery. It is occupied by the Lower Old Sandstone with its included conglomerates, flagstones, and volcanic rocks. A remarkable dislocation, which nearly coincides with the line just traced, separates the younger series of formations from the older rocks of the mountains. But here and there on the north side of the fracture, in bay-like hollows of the hills, the massive conglomerates of the Old Red Sandstone can be seen rest ing upon the upturned edges of the schists. These con glomerates with their associated strata appear to have been laid down in a large lake or inland sea which lay across central Scotland and northern Ireland, and was tenanted by the peculiar Old Red Sandstone fishes (Cephalaspis, &c.). A long line of active volcanoes extended through this lake. Their sites are still traceable in the Ochil and Sidlaw Hills. See GEOLOGY, vol. x. p. 343 sq. Much of the lower ground is covered with the clays, gravels, and sands left by the ice- sheets and glaciers that once occupied the surface. Raised beaches marking recent upheaval of the land are seen in the Firth of Tay. The larger rivers present a succession of three or more alluvial terraces. Copper ore is found in the southern Ochils and coal at their base. Ironstone is wrought at Culross. Lead and other metals are found sparingly in the neighbourhood of Tyndrum, Ben Ledi, and Glen Lyon. Roofing slates are quarried at Birnam. In many valleys there are large deposits of peat. Agriculture. The climate and soil of Perthshire present greater varieties than in any other county of Scotland. In the higher western regions it is very moist ; and long stretches of exposed uplands alternate with finely-sheltered valleys. The arable land is chiefly in the drier eastern districts. For the most part the soil is sharp and fertile. The county, agriculturally, may be classed in four divisions : deer-forests, chiefly the wilder mountain districts ; grazing and pasture lands on the hills, embracing about four-fifths of the total area ; light soils in the lower undulating dis tricts, including the north portion of Menteith and the upper portion of the principal river- valleys, specially suited for oats, barley, turnips, and potatoes ; clay and carse land, chiefly in the Carse of Gowrie, which extends to about 100,000 acres, in the Carse of Stirling north of the Forth and in the lower part of Strathearn below and above Bridge of Earn. The Carse of Gowrie has as its basis the boulder clay, above which rests the blue clay proper, or peat, or the carse clay, a mixture of sand and clay, ranging from the finest clay soil to poor whitish "end clay." The best heavy carse land is very rich and productive, but requires to be thoroughly wrought, limed, and manured. The dis trict is well adapted for wheat, although the area sown is decreasing. A considerable area is occupied by orchards, the light quick soil on Tayside and in the upper districts of Menteith being admirably adapted for apples. Between 1875 and 1880 the number of holdings decreased from 5296 to 5123, although their area increased from 331,890 to 344,728 acres. Of the holdings 179 in 1880 were above 300 acres in extent, 1033 between 100 and 300 acres, 786 between 50 and 100 acres, and 3125 did not exceed 50 acres each. There are a large number of small holdings in the Highland valleys and in the neighbourhood of the villages and small towns. According to the agricultural returns for 1883 there were 344,240 acres, or only a little less than a fifth of the total area, under cultivation, 103,050 acres being under corn crops, 50,799 acres green crops, 100,631 rotation grasses, 87,064 permanent pasture, and 2696 fallow. Of the corn crops, 70,424 acres were under oats, 22,770 acres barley and bere, 6238 wheat, and 3087 beans ; and of the green crops, 31,059 acres were under turnips and swedes and 18,611 under potatoes. The number of horses was 13,651, of which 10,524, chiefly Clydesdales, were used solely for agricultural purposes. Cattle numbered 73,097, of which 18,755 were cows and heifers in milk or in calf. Although dairy-farming is not in itself an im portant industry, a large number of cows are generally kept on the lowland farms. The cows are principally Ayrshires, but the West