A lonely road leads to the entrance, from which, as we approach it in summer, we find a peculiarly chilly air issue forth. The sombre gloom of the entrance does not prepare us for the enormous hall within; long avenues leading into vast chambers, the smaller, thirty feet in height, at least, with an area of half an acre, and, as we get lower and lower, increasing in height. Upwards of eighteen miles of the cavern have been explored, and it may possibly be of still greater extent. To give an idea of the height of one of the chambers, we may add that the rocks from above have fallen, and a hill has been formed one hundred feet in elevation. Many of the halls are ornamented with the most magnificent stalactites. One of them is appropriately called Martha's Vineyard, in consequence of having its tops and sides covered with stalactites which resemble bunches of grapes. Several streams pass through the cavern, down the sides of which rush numerous cataracts. Some of these streams, which are of considerable depth and width, are inhabited by shoals of eyeless fish, the organs of sight being superfluous in a region doomed to eternal night. The atmosphere of this huge cave is peculiarly dry, and is supposed to be extremely serviceable to persons afflicted with pulmonary complaints. To visit any considerable portion of the cavern would occupy us at least a couple of days. It is calculated there are no less than two hundred and twenty-six avenues, forty-seven domes, numerous rivers, eight cataracts, and twenty-three pits,--many of which are grand in the extreme. Some of the rivers are navigated by boats, and, as may be supposed, they have obtained appropriate names. Here we find the Dead Sea and the River Styx. One of the streams disappears beneath the ground, and then rises again in another portion of the cavern. But after all, as naturalists, the little eyeless fish should chiefly claim our attention. OIL SPRINGS. As coal was stored up for the use of man, formed in ages past from the giant vegetation which then covered the face of the earth, so the Creator has caused to be deposited in subterranean caverns large quantities of valuable oil, which not only serves man for light, but is useful to him for many other purposes.