Although I have not seen Herr Hübner’s “Klippdachs-Schlucht,” I imagine it must be included in the category of these formations. I found, too, that many small streams in the district of the Vaal, the Harts River, the Molapo, and the Marico, as well as in that of the Upper Limpopo, had their origin in similar hollows in the rock, where the water could not immediately run off, but collected in the funnel until it forced its way through. At most of the farms near such streams we noticed how the supply of water issued from a marshy spot, perhaps a mile or so higher up, and how in the very midst of the springs there was frequently a cavity, perhaps fifty feet or more in depth, that had all the appearance of having been bored in the rock.
In every place of this character, even where the water had only a subterranean outlet, I invariably found that there were none but the same species of fish. I know a reedy pool on a plain between the Harts River and the Molapo, abounding with fish and birds, which appears to have no outlet whatever; and having ascertained that its greatest depth is near the middle, I have no doubt but that it is an example of these open funnels in the rock. In the limestone where these singular formations exist, besides veins of quartz and quartzose mineral, there are to be found particles of tin, copper, iron, and silver.
It was on the third day after leaving Potchefstroom that we arrived at Wonderfontein. This is the name by which the Boers distinguish the caves and grottoes of the district, and which does not belong as usual to a single farm, but to a series of farms that with their separate pasture-lands lie along the valley of the Mooi River. The farm-houses are chiefly built of stone, and are buildings of good elevation, each being provided with a waggon-shed, and with one or more rush-huts for drying tobacco, which is universally cultivated in this part of the country. The particular farm to which we were now directing our course was in the immediate vicinity of the “wonderful” caves, and might be termed Wonderfontein proper.
Fed by numerous streams that flowed from both directions, the Mooi River was here of comparative importance; its banks in places were swampy, and overgrown with masses of reeds, yielding an unfailing source of interest to the ornithologist; and so confusing was the chorus of whistling, twittering, cackling, and singing, that we could hardly fail to be puzzled as to where we should give our attention first.
GROTTO OF WONDERFONTEIN.
By the permission of the farmer we made our camp under some weeping willows that overhung his peach-garden. We made many inquiries about the grottoes, and were told that as it was quite easy to find the entrance it was equally easy to miss the way inside, and to fail to find an exit; it was therefore advisable to be provided with guides. This office, we were soon informed, could be undertaken by the two sons of the farmer for the remuneration from our party of 1l. a head. Exorbitant as I felt the demand was, yet having come to Wonderfontein for the express purpose of visiting the caves, I submitted to the exaction without a murmur. Some relations of the farmer, who were staying with him on a visit, proposed to join us, and we started without much delay, the two guides each carrying a bundle of tallow candles.
Having crossed the little river by a ford, wide bub quite shallow, we had to clamber up the right bank, which was very rocky, and covered with bushwood. A quarter of an hour brought us to a chasm in the rocks, opening almost perpendicularly downwards, and which was manifestly another of the funnels which I have been describing. The entrance to the cavern was a clear illustration of the rending of the rocks, but I must own that I was considerably disappointed with the interior. I had expected to find fossil remains of the late geological period, and thereby perhaps to supply a gap in the geological records of South Africa; but I found nothing to gratify my anticipations.
By the help of the rocks projecting from the sides of the funnel, we managed to descend to the bottom, which had gradually contracted until it was only a narrow passage slanting down towards, or it might be below, the river-bed. Here we entered upon a perfect labyrinth of fissures, at first so small that we could only creep in one after another on all fours, but increasing till they were frequently ten feet high; they terminated above in mere clefts, from which the water kept dripping, and formed stalactites that were not exceptional in character, either of form or size; they had nearly all been damaged by previous visitors, and the ground was covered with their fragments.
The very multiplicity of the underground passages through which we were conducted, was in itself a proof that the rock had been rifted in all directions, and in many places where the two clefts came into connexion, a sort of vault was formed overhead, somewhat higher than the passages, but presenting no other remarkable feature. The sides were dark grey, generally bare and smooth. The little brook, of which we could hear the sound as soon as we entered, rippled through the caves from east to west, and covered the breadth of the passage, making it necessary for us to perform the best part of our excursion barefooted. As we went onwards, either to the west or north, the water became considerably deeper; we caught sight of some stalactites, glistening and undamaged, just before us, but were prevented from securing them by our guides, who refused to advance a step further.