THE VEGETATION OF NATAL. 261 



coast, carrying above it moisture-laden warm air. A counter 

 current close to the land flows northwards, and, it being a 

 cold current, carries above it colder air. At Port Durnford, 

 owing to the coast-line bending outwards, the cold current is 

 forced to bend round also. The two currents meet, and the 

 warmer air has to deposit its moisture. This rain, Mr. 

 Hammar informs me, rarely extends more than a few miles 

 inland. 



D. From the coast landwards the rainfall decreases till the 

 edge of the first terrace is reached. Here the land rises 

 steeply for 1000 feet or so, and with the rising altitude 

 the air, becoming less dense, is forced to deposit more of its 

 moisture. Places at the edge of this terrace have again, there- 

 fore, a higher rainfall. The rain clouds do not, however, deposit 

 much of their moisture in the deeply cut river valleys. After 

 the rain-clouds have passed upwards on to the first terrace 

 we have a repetition of what happened from the coast inland. 

 Less and less moisture is deposited till the edge of the next 

 terrace is reached, where the land again rises steeply. Then 

 the rainfall is again greater and so on. Finally the Drakens- 

 berg Range is reached, the region of heavy rain-storms in 

 summer and snow in winter. 



2. Mist. — In addition to the actual rainfall recorded the 

 &,mount of moisture condensed as dew and mist is of enormous 

 importance. Reference may be made to the experiments 

 carried out by Dr. Marloth under the famous mist-cloud or 

 " tablecloth " of Table Mountain, Cape Town. He used two 

 rain-gauges, one exposed in the ordinary way, the other placed 

 underneath a framework, on which rushes one foot high 

 were placed. From December 21st, 1902, to February 15th, 

 1903, he collected in the open rain-gavige 4"97 in., while in 

 the other he obtained 79-84 in., and he states : " It is not too 

 much to assume that, as the season of south-east clouds 

 extends over double that time, there would consequently be 

 a condensation of moisture exclusive of all rain of at least 150 

 inches during the summer alone." 



In Natal the same thing happens. Under the mist-clouds 



