321. In small lakes, this progress may easily be traced; and will be found singularly conspicuous in that beautiful assemblage of lakes, which so highly adorns the mountain scenery of Westmoreland and Cumberland. Among these a great number of instances appear, in which lakes are either partially filled up, or have entirely disappeared. In the Lake of Keswick, we not only discover the marks of filling up at the upper end, which extend far into Borrowdale, from which valley a small river flows into the lake; but we have the clearest proof, that this lake was once united to that of Bassenthwaite, and occupied the whole valley from Borrowdale to Ouse-Bridge. These two lakes are at present joined only by a stream, which runs from the former into the latter, and their continuity is interrupted by a considerable piece of alluvial land, composed of beds of earth and gravel, without rock, or any appearance of the native strata. This separation, therefore, seems no other than a _bar_, formed by the influx of two rivers, that enter the valley here from opposite sides, the Greata from the east, and Newland's water from the west. The surface of this meadow is at present twelve or fifteen feet at least above the level of either lake and a quantity of water of that depth must therefore have been drawn off by the deepening of the issue at Ouse-Bridge, through which the water of both lakes passes, in its way to the ocean. Many more examples, similar to this, may be collected from the same lakes; there are indeed few places from which, in this branch of geology, more information may be collected. 322. The larger lakes exemplify the same progress. Where the Rhone enters the Lake of Geneva, the beach has been observed to receive an annual increase; and the Portus Valesiæ, now Port Valais, which is at present half a league from the lake, was formerly close upon its bank. Indeed, the sediments of the Rhone appear clearly to have formed the valley through which it runs, to a distance of about three leagues at least from the place where the river now discharges itself into the lake. The ground there is perfectly horizontal, composed of sand and mud, little raised above the level of the river, and full of marshes. The deposition made by the Rhone after it enters the lake, is visible to the eye; and may be seen falling down in clouds to the bottom.