THE SWEET SPRINGS OF VIRGINIA, AND THE VALLEY WHICH CONTAINS THEM.
BY W. BYRD POWELL, M.D.
Mr. Jefferson has said, and we admit it, that a sight of the Natural Bridge is worth a trip across the Atlantic. But as this does not preclude the possibility of greater curiosities existing, we are allowed the privilege of expressing the belief, that the Sweet Springs, inclusive of the entire valley which contains them, present to a philosophical mind, a scene of incalculably greater interest. The bridge, by one mental effort, is comprehended, and speculation put at rest. Not so with this valley; but like the bridge, the first impressions produced by it create amazement, but as soon as this state of feeling is displaced by further observation, a train of thought succeeds, of unceasing interest, upon the character and variety of the causes which could have produced such a pleasing variety of effects.
In the first place, the several springs, bubbling forth immense volumes of water, highly charged with lime, carbonic acid gas, free caloric, and in some instances iron, are objects of peculiar interest to the philosopher, and so they will remain, more especially, until more facts in relation to them are discovered, and the laws of chemical affinity are better understood.
In the second place, the great fertility of the valley, even to a common observer, will be remarked as a matter of very uncommon occurrence.
In the third place, those elevations which cross the Valley, five in number, popularly known as the Beaver Dams, are marvellous matters, transcending even the Natural Bridge; and that they were constructed by beavers, cannot admit of a doubt. But then the mind is lost in amazement at the probable number of the animals that inhabited the valley, and the immensity of their labor.
The valley is bounded by high hills, perhaps mountains, and the one that terminates its lower extremity consists of slate, and is separated from the lateral ones by a stream of small magnitude above its junction with the valley branch, which is made up measurably of the mineral waters. The lateral mountains, at their lower extremity are slate; at the other, sandstone; and in the middle, limestone.
From the upper spring, or the one now in use, to the junction of its branch with the mountain stream above treated of, is three miles, and the fall in that distance was originally about one hundred and fifty feet. Then there was between these lateral hills no valley or flat land—this has been produced by the Beaver Dams which divided the original declination into five perpendicular falls, measuring each from twenty to thirty-eight feet—thus producing out of one mountain gutter, five beautiful tables of the richest soil in the world. And this too, simply by retaining the debris from the surrounding hills, as it was annually washed in, and also the lime from the mineral waters, which, since the production of the fountains has been constantly depositing. It is furthermore evident that no one of these dams was the work of one season, but of many, just as the necessity for elevation was produced by the filling up of the artificial basin.
As a description of one of those dams will serve for all, we will take the largest, and the one which bounds the lower extremity of the valley.
This dam constitutes one bank of the stream which receives the valley waters, and is about thirty-eight feet high, and half a mile in length; the elevation, however, gradually diminishes from the centre to the extremities. The mineral waters of the valley contain, as we have intimated, an immense quantity of lime, which is deposited with astonishing rapidity in the state of a simple carbonate, (especially in those places where the water has much motion,) producing those mineral forms called stalactites and stalagmites. With this knowledge it is easy to comprehend how these imperishable monuments of beaver labor and economy were produced.—For instance, these animals, according to their manner of building, felled trees across the mouth of the branch, and filled smaller interstices with brush, which would cause motion in the water and serve as nuclei for its mineral depositions. Consequently, in this dam may be seen immense incrustations of logs, brush, roots and moss. In many instances, the ligneous matter, not being able to resist the decomposing effects of time and moisture, is entirely removed, leaving petrous tubes, resembling, in the larger specimens, cannon barrels. These calcareous deposites not only cemented the timber together, but secured the entire work against the smallest percolation, prevented the escape of mountain debris, and rendered permanent a labor, which under other circumstances, would little more than have survived the duration of the timber, or the life of the industrious artificer.