i 32 DISCOVERY REPORTS 



The generally accepted theory that the cold current along the coast was a direct flow from high 

 southern latitudes was held until the middle of the nineteenth century, although Rennell recognized 

 a continuity in the surface drift from the Indian Ocean to the Atlantic, around the Cape of Good 

 Hope. Sir James Clark Ross (1847) on his passage to the Antarctic carried out a series of temperature 

 measurements around the Cape, which show conclusively that the cold water on the west coast was 

 an isolated phenomenon, and was not continuous to the south. Whilst approaching the African Coast 

 in the vicinity of Paternoster Point on the 8 March 1840, he remarks: 



By 1 p.m. the next day the temperature of the sea had fallen from 70 to 56-5° F., that of the air being 65 ° and 

 the mist unpleasantly cold to our feelings. We were at this time in 32° 21' S., 17° 06' E., therefore about 45 miles 

 from Paternoster Point, when we struck soundings in 127 fathoms on a bed of fine dark sand. We had expected 

 to have found an elevation in the temperature both of the air and sea on our approach to the African coast, by 

 reason of the heat radiation from its shores ; but the cause of the depression became evident on the morning of 

 the 9th, when having sighted Cape Paternoster at daylight, we found we had to contend against a current increasing 

 in strength and coldness of temperature as we neared the land. 



Ross had to spend several days beating up to the Cape, and while doing so he took the opportunity 

 of making observations of temperature at different depths and distances from the land. These he has 

 tabulated, and from them he concludes : 



All these circumstances combine to show that a northerly current of very limited extent, but of considerable force 

 exists from the Cape of Good Hope, along the western coast of Africa; which in general terms, may be represented 

 by a volume of water sixty miles wide and two hundred fathoms deep, averaging a velocity of one mile per hour, 

 and of the mean temperature of the ocean, running between the shores of Africa and the waters of the adjacent sea. 

 The cloud of mist which hangs over this stream of cold water is occasioned, of course, by the condensation of the 

 vapour of the superincumbent atmosphere, whose temperature is generally so many degrees higher than that of 

 the sea. It is sufficiently well defined to afford useful notice to seamen of their near approach to the land. 



After leaving Simon's Town, Ross continued his temperature measurements, and 

 found the temperature of the surface of the sea to increase rapidly after leaving Cape Point, . . .showing that we had 

 got to the southward of the cold water current that runs along the west and perhaps the south coast of Africa. 



It is evident therefore that this current does not come down directly from the south, as it only extends to seven 

 or eight miles from the Cape and beyond that distance we have to descend to over six hundred fathoms to find 

 water of so low a temperature. 



These observations do not appear to have received very wide attention, for even up to 19 10 

 (Engeler), some authors upheld the continuity between the West Wind Drift and the cold current on 

 the west coast of South Africa. Findlay (1874), Bourke (1878) and Gallon (1883) all speak of a south 

 polar current on this coast, although Bourke appears to have been mystified by the patchy distribution 

 of the cold water. 'But the most remarkable feature of this N.W. current from the Cape of Good 

 Hope is the sudden manner in which its cold waters simultaneously appear along the land to the 

 northward of Cape Frio.' 



The origin of the cool water by upwelling was inferred both theoretically and by comparison with 

 other regions by Witte (1880), Buchan (1895) and Schott (1902). It was finally confirmed by the 

 serial oceanographical observations of S. M. S. 'Mowe' (Schott, Schulz and Perlewitz, 1914). 



Many early writers on the region make general references to its great wealth of marine life. 

 Pechuel-Loesche (1882, p. 283) writes of 'a species of herring Pellona africana that presses shorewards 

 from the South Atlantic current in immense shoals, from November to February '. Though most of 

 his observations were made far to the north, where the upwelling is a much more seasonal phenomenon 

 than in the region off South-west Africa, the analogy with the behaviour of other clupeoids farther 

 south is most striking. Pechuel-Loesche also appears to be responsible for the present name of the 

 current. 



