Results of further Experiments on Table Mountain. 103 



however, leave this figure out of account altogether, for the gauge 

 which was practically hidden in the reeds, just as if it were standing 

 in the midst of a luxuriant cornfield, showed 6*1 inches of moisture, 

 and that for a period of six days, during which the ordinary rain- 

 gauge at Maclear's Beacon recorded 0*15 inches of rain. I think it 

 will be admitted that there are no other figures wanted. As a matter 

 of fact, for any one who visited the mountain on that day or soon 

 afterwards no figures were necessary at all to convince him of the 

 enormous quantity of water which this south-easter had left on the 

 mountain. 



The upper plateau was practically a swamp from one end to the 

 other ; everywhere one met with pools of water ; the little lake on 

 the top had double the size and depth it usually possesses at the end 

 of the summer, and the few late blooms of the gorgeous Disa uniflora, 

 which I found in the fir-tree valley, were partly submerged on the 

 borders of the swollen stream. And there had been no rain worth 

 mentioning for 23 days. 



As stated in my previous paper, I do not look upon these figures 

 as being equivalent to records of rainfall as far as the general water 

 supply of the streams is concerned, for during rain a great deal of 

 water runs off from the bare rocks and reaches the streams imme- 

 diately, while this moisture is captured only where sufficient vegetation 

 exists, which, on the other hand, retains a large proportion of it in the 

 spongy root work. Yet observations and gaugings made at some of 

 our larger mountain streams have shown, that a considerable rise of 

 the rivers may be effected by a long-continued south-east wind, 

 although no rain had fallen in the catchment area. 



There can be no question that the vegetation of our mountains is 

 a very important factor in the regulation of the water supply of the 

 springs and streams, and that this influence is exerted in two ways. 

 Firstly, by capturing a not inconsiderable amount of moisture from the 

 south-east clouds, which would escape if the mountains were formed 

 by bare rocks only ; and, secondly, by protecting the water which has 

 accumulated in the soil and the rocks against the sun and consequent 

 rapid evaporation. With regard to the loss due to evaporation I may 

 be allowed to mention the experience of the Cape Orchard Company 

 at Hex Eiver. 



Mr. Dicey has kindly informed me, that the mountain stream, 

 which the Company uses for driving their Pelton wheel, gives them 

 in summer 60 horse-power, but that on bright days the quantity of 

 water in the stream generally decreases so much that about 2 p.m. 

 they cannot obtain more than 55 or 54 horse-power. Towards even- 

 ing it rises again and regains its full force by 11 p.m. 



