NATURAL HISTORY. 65 



are felt on one side of the mountains, and all the rigours 

 of winter on the other. The same phenomenon is also 

 observed at Cape Rozalgate in Arabia, and on the island 

 of Ceylon. 



In Egypt during summer, a south wind prevails which 

 is so hot as to stop respiration ; and it raises so great 

 a quantity of sand, that the sky seems covered with 

 thick clouds. This sand is so fine, and driven with 

 such force, that it penetrates every where, even into the 

 closest coffers. When these winds last several days 

 they occasion epidemical diseases, which are often at- 

 tended with the most fatal consequences. 



The Cape of Good Hope is famous for its tempests, 

 and the singular cloud which produces them. This 

 cloud appears at first only like a small round spot in 

 the heavens, called by the sailors the Ox's eye, and 

 which I imagine appears so little from its exceeding 

 great height. In Natolia, a cloud similar to the Ox's 

 eye at the Cape, produces the same direful effects. In 

 -the sea between Africa and America, especially under 

 the equator and in the neighbouring parts of it, those 

 tempests very often arise ; near the coast of Guinea 

 sometimes three or four of these storms are formed in 

 a day. They are occasioned and announced, like those 

 of the Cape, by small black clouds. The rest of the 

 sky is generally very serene, and the sea calm. The 

 first blast which issues from these clouds is furious, and 

 would sink ships in open seas, if they did not take the 

 precaution to furl the sails. It is principally in the 

 months of April, May, and June, that these tempest* 

 are experienced on the Guinea sea, because no regular 

 wind blows there during the season. 



All these tempests originate from winds which issue 

 from a cloud, and their direction is either to the north 



Val. I. H 



