The principal rivers in this county, or waters as they are provincially termed, are, 1. The .Ar.irth Esk. This river takes its rise from Lochlee, whose waters are sup plied by many small streams, which flow from the neigh bouring mountains. It descends from the high grounds with considerable rapidity, and, after having been joined by several small streams, as the Mark, the Tarf, the West Water, and the water of Cruick, it empties itself into the German Ocean, about three miles north-east of Montrose. 2. The South Esk likewise has its rise from a small lake arising among the Grampians, fed by the moun tain-streams of Clova. Descending from the Grampians, it receives several subordinate streams, and, after passing by Brechin, empties itself into the basin at Montrose. 3. The Isla is another of the streams which rise in the Gram pian mountains. Its channel is deep, and in the course of its descent exhibits many fine cascades. In the low grounds its motion becomes less rapid, until it falls into the river Tay in Perthshire. The streams called the Dean, the Lunan, the Dichty, and the Brotheck, are too inconsider able to be ranked as rivers.
The surface of this district is greatly diversified in its appearance. On its northern and western limits, the Grampian mountains rise in lofty grandeur, and exhibit all the varied scenery of an alpine country. They are here termed the Braes of dIngus, and in some places possess an elevation of nearly 3000 feet. To the south of the base of the Grampians, and at the distance of four or five miles, another range of hills appears, with a character less bold and majestic, known by the name of the Sidlaw hills. These are to be considered as a continuation of the Ochils, as they are composed of the same materials, observe the same direction, and exhibit, with these, an almost uninter rupted continuity. This range does not greatly exceed 1000 feet in height above the Tay. It traverses the whole extent of the county from Montrose to Lundie. Amidst the Grampian mountains, and even among the Sidlaw hills, there are numerous wallies, which add beauty to the sce nery, and give fertility to the district. But these wallies appear as nothing, when compared with that extensive plain situated between the Grampians, on the one hand, and the Sidlaw hills on the other, called and some times termed by the natives the How of Angus. This great valley runs parallel with the Grampians from their com mencement in Dumbartonshire, to their termination on the borders of Aberdeenshire. This great valley, in which the -hand of the manufacturer will ere long dig a canal, and spread the sail of c0111111erCE, is scarcely elevated 200 feet above the level of the sea. It would appear from the stra
tified hills of gravel which here and there appear, and from all the other phenomena of the valley, that it was the ha sin of an extensive lake, fed probably by many of those streams which at present flow through other districts, ow ing to the changes which the Grampians have undergone by the hand of time.
The county of Angus presents to the mineralogist a fine field for the display of his powers of investigating na ture. No less than four classes of rocks make their ap pearance : The primitive, the transition, the flcetz, and the alluvial.
The rocks of the primitive class are granite in small portions, gneiss, mica slate, and clay slate. The granite presents several varieties, with respect to the size of the grain, and the colour of the felspar. In some instances it is fine-grained, and bears a close resemblance to the gra nite of Aberdeen. The variety termed Pierre graphigue, and a still more uncommon variety, in which the felspar assumed a rose colour, were observed by Colonel hnrie. This granite occupies the centre of the Grampians, and appears to be the fundamental rock. It contains rock crystal, called Cairngorum, and topaz. Gneiss is a very prevalent rock in this district. It rests upon the granite, and is fine-grained, compact in its texture, and usually of a grey colour. It contains in several places beds of horn blende rock. Mica slate is by far the most abundant rock. The mica which it contains , termed sheep's Biller. It seldom contains garnets. r;ranular limestone is by no means of rare occurrence ; z ,c1 were the Highlanders dis posed to burn it, they would soon improve their pastures. Peat is at hand, and answers well as fuel for the purpose. Clay slate occurs in the less elevated districts ; but in these strata no good beds of roof slate have as yet been discover ed, owing probably to want of skill and industry. These primitive rocks are traversed by veins of porphyry, con sisting of a basis of compact felspar, with crystals of fel spar, and grains of quartz. These veins are from 8 to 10 feet in breadth, and although occurring at considerable dis tance from one another, yet they all observe the same di rection. They stretch nearly from south to north. Lead glance has also been found in veins among these rocks. It was formerly wrought to a considerable extent near the old castle of Innermark, and yielded a sixty-fourth part of silver.