Overhanging the brooks that ripple in gutters along the streets, are fine weeping willows, that afford a refreshing shade from the glowing sunbeams; their light green leaves and slim drooping boughs stand out in elegant contrast alike to the compact growth of the fruit-trees, to the dark foliage of the eucalyptus, to the pointed shoots of the arbor vitæ, and to the funereal hue of the cypress.
It was evening when we next started, taking an east-north-east direction, to proceed towards the Mooi. We had scarcely left the town behind us when we began to experience the greatest difficulty, on account of the mud, in making our way over the few hundred yards that led to the primitive bridge across the river.
Our route next morning lay through a wide valley, open in most directions, in which was a farmstead consisting of several buildings, and carefully enclosed by its own fields and well-kept garden. Having here obtained some gourds, we proceeded nearly east, and soon reached a table-land, bounded on the south by a chain of hills partially covered with trees. In other quarters we had an uninterrupted view of the river-valley with its numerous farms, to be recognized everywhere by the dark patches of cultivated land; in the extreme distance were ridges of hills and isolated heights, and the slope of the Blue-bank plateau; while on the northern horizon we could just discern the outline of the Magalies mountains. It was the finest view I had hitherto seen.
NIGHT CAMP.
On the table-land that we were crossing, I noticed some funnel-shaped chasms in the soil, varying from twenty-five to forty feet in depth, distinguishable from a distance by the thickness of the growth of the trees. I afterwards learnt that similar chasms are by no means uncommon in some parts of the Transvaal, between the Harts River and the Molapo, as well as between the Lower Molapo and the Vaal in the Barolong and Batlapin territory; they are found likewise in Griqualand West. These crater-like openings are characteristic of the vast bed of superficial limestone that lies, sometimes indeed only in thin layers, but ordinarily some hundreds of feet thick, covered in some places with sand or chalk, and in others with blocks of granite or slate; they are caused by the union of several deep fissures in the rock far below the surface of the soil. This limestone-bed has a clearly defined stratification; it bears external marks of the action of water, and throughout its extent of hundreds of miles is full of cracks, but so hard is its substance, and so huge is its mass, that in nine cases out of ten the convulsions of nature have not made any appreciable displacement; it is only in these chasms that the effect is at all apparent.
FUNNEL-SHAPED CAVITY IN ROCKS.
The underground fissures, sometimes several miles long, serve as subterranean channels for the streams, which after a while force themselves out through little rifts into the valleys. This is the case with the Upper Molapo, and in the same way does a portion of the Mooi flow below the surface of the ground, disappearing entirely in places, to reissue further down the valley. Where, however, several fissures are concentrated at one point, they result in the formation of the craters to which I refer. At the top, these funnels are sometimes as much as 200 or 300 yards in circumference: at first sight they have the appearance of being circular, but on investigation they nearly always prove triangular, or, less frequently, quadrilateral. The interstices of broken rock with which their inner surface is lined are filled up by the surrounding earth, which thus forms a luxuriant bed for the roots of trees and shrubs, which tower up above, and become conspicuous upon the generally barren plain.
Where the fissures that radiate from the bottom of the funnels are sufficiently wide at the top, it is quite possible to descend perpendicularly for a short distance and to trace their course sometimes for several hundred yards. Many of them are full of water clear as crystal, and one that I saw subsequently, on my way back from my third journey on the Upper Molapo, was full to the depth of 140 feet, so that I might almost feel justified in describing it as a miniature lake.