and rock at the bottom you may walk across dry. This cataract will bear no comparison with that of Niagara, as to the quantity of water composing it; the sheet being only 12 or 15 feet wide above, and somewhat more spread below; but it is half as high again, the latter being only 156 feet, according to the mensuration made by order of M. Vaudreuil, Governor of Canada, and 130 according to a more recent account.
In the Lime Stone country there are many caverns of very considerable extent. The most noted is called Madison's Cave,[1] and is on the North side of the Blue Ridge, near the intersection of the Rockingham and Augusta line with the South fork of the Southern river of Shenandoah. It is in a hill of about 200 feet perpendicular height, the ascent of which on one side is so steep, that you may pitch a biscuit from its summit into the river which washes its base. The entrance of the cave is in this side about two-thirds of the way up. It extends into the earth about 300 feet, branching into subordinate caverns, sometimes ascending a little, but more generally descending, and at length terminates in two different places at basons of water of unknown extent, and which I should judge to be nearly on a level with the water of the river; however, I do not think they are formed by refluent water from that, because they are never turbid; because they do not rise and fall in correspondence with that in times of flood, or of drought, and because the water is always cool. It is probably one of the many reservoirs with which the interior parts of the earth are supposed to abound, and which yield supplies to the fountains of water, distinguished from others only by its being accessible. The vault of this cave is of solid lime stone, from 20 to 40 or 50 feet high, through which water is continually percolating. This, trickling down the sides of the cave, has incrusted them over in the form of elegant drapery; and dripping from the top of the vault generates on that, and on the base below, stalactites of a conical form, some of which have met and formed massive columns.
- ↑ See Map No. 2, App. iv.
