CURRENT OFF THE CAPE. 345 



The current which prevails over this bank has been the 

 subject of much speculation, and Major Rennell took great 

 pains to explain its direction and velocity. For this pur- 

 pose he published a chart of the bank for the winter months. 

 It must be evident that such a chart could only be used for 

 general purposes ; for the current is found to vary in the 

 same months of different years,— is often obstructed and 

 changed in its direction by gales of wind, — sometimes ceas- 

 ing altogether even in fine weather. A variety of opinions 

 exist as to the originating cause of this current. The most 

 <renerally received is the following :— By the constant action 

 of the south-east trade-wind, the water of the great Indian 

 Ocean is displaced, or forced before the breeze to the north- 

 westward, round the north end of Madagascar, finds its 

 way to the southward through the Mozambique, and takes 

 a westerly direction round the Cape. To account for this 

 westerly direction, it must be observed that the constant 

 action of north-west and westerly winds on the west side 

 of the Cape causes a displacement of water, which the 

 westerly current runs to replace. It must be sufficiently 

 obvious, that if this is the true theory on the subject, it be- 

 comes impossible to give any specific rules for determining 

 with accuracy either the duration, velocity, or direction of 

 this remarkable current. After a gale from the westward, 

 if the current has been repressed by the gale, it generally 

 runs with redoubled velocity. The current is generally 

 weak near the land, and the sea smooth. Horsburgh gives 

 the following as the general course of the current : — " In 

 June, July, and August, from about long. 37° or 40° east, 

 the current generally sets westward between lat. 30° and 

 35° south, tifl it reaches the eastern part of the Cape Bank, 

 otf Algoa Bay. On the coast of Natal it sets along-shore 

 to south-westward, till joined by the oceanic stream on the 

 «dge of the bank in 27'^° or 28° east long., between Algoa 

 Bay and Infanta River. After the junction it increases in 

 strength abreast of Algoa Bay, and takes the direction of 

 the outline of the bank, which is west-by-south nearly, to 

 long, about 23 i° west. In this space it often diverges a 

 little from the outline of the bank, setting west-by-south 

 one-half south, or west-south-west, but seldom if ever west- 

 north-west or west-by-north, as represented by the charts. 

 In long. 23i° east, the edge of the bank begins to take a 



