422 W. M. DAVIS OBSERVATIONS IN SOUTH AFRICA 



the railway line soon shows. The surface has broad swells of very faint 

 convexity between broad depressions of equally faint concavity, and it 

 may therefore be called a peneplain instead of a plain, as if it represented 

 the penultimate and not the ultimate stage of the geographical cycle. The 

 Veld is not a surface of accumulation or of construction ; it is a surface 

 of erosion, for the various formations of the Karroo system of which the 

 region is built up are often seen under the thin soil, obliquely beveled by 

 the gently undulating plain. Moreover, the Veld is frequently sur- 

 mounted in one district or another with ridges and tables of resistant 

 dolerite, whose occurrence demands the former presence of higher Karroo 

 beds to an additional thickness of hundreds or thousands of feet. Again, 

 certain parts of the Veld are not reduced to so small a relief as those 

 just referred to, and hence seem to show a less advanced stage of develop- 

 ment; here the more distinct swells and troughs are called bults and vleis 

 by the Boers. 



It should not be understood, however, that in considering the highland 

 of the Veld as a peneplain it is intended to imply that it stands at one 

 level over its great extent. A peneplain must have a perceptible measure 

 of residual relief ; its streams must exhibit a gentle slope, and hence, when 

 its surface extends over hundreds or thousands of miles, it is essential 

 that its different parts should be of different altitudes. Just what the 

 existing differences of altitude amount to it will be impossible to say 

 until the region is surveyed. It is evident that the openness and prevail- 

 ing smoothness of the Veld has favored the advance of settlement 

 across it. 



It is especially noteworthy that the faint depressions of the Veld are as 

 a rule not undrained hollows (we saw few "pans" on our journey), but are 

 arranged in branchwork fashion, systematically joining one another down- 

 stream in a way that can be explained only by long-continued river work ; 

 the faint depressions are indeed nothing more nor less than valleys in 

 their old age, although they are as unlike the steep-sided troughs which 

 the term valley ordinarily suggests as the faint swells of a worn down 

 range are unlike the mountains from which they have been reduced. 

 This old drainage system seems thoroughly organized, although not very 

 energetic, all its parts being closely interdependent and everywhere show- 

 ing that wonderfully delicate adjustment of declivities which brings the 

 graded lines of interstream slopes into accordant junction with the stream 

 courses, and the stream courses with each other. On the surface thus 

 fashioned the drainage system seems, precisely as the theory of the cycle 

 leads one to expect, everywhere just competent to do its duty — that is, to 

 carry along the waste that is washed from the broad surface of the faint 



