"Secondly, These vapours must be extremely embarrassed in their road, by the frequent shocks and counter shocks caused, not only by the mountains, but also by the south and east winds which reign at places circumjacent to the Cape: I have already spoken of the two mountains called Hanging Lip and Norvege, situate on the points of False Bay; when the particles which I conceive are impelled on these mountains by the easterly winds, they are repelled from them by the south, which carry them on the neighbouring mountains; they are stopt there and appear like clouds, which is often the case upon the mountains of False Bay. These clouds are frequently very thick above the land which the Dutch are in possession of, on the mountains of Stenltenborch, of Drakenstein, and Stone, but particularly on the mountains of the Table, and of the Devil. "In short, what confirms me in my opinion is, that constantly two or three days before the south-east wind blows on the Lion's Head, small black clouds are perceived above it; these clouds, according to my opinion, are composed of the particles or vapours which I have spoken of. If the north-west wind prevails when they arrive there, they are stopped in their course, but are never driven to a great distance till the south-east winds commence." The first mariners who approached the Cape of Good Hope were ignorant of the effects of these clouds, which appear to form in the air so slowly, and without any motion, but which in a moment excite the most dreadful storms that precipitate the largest vessels to the bottom of the sea. In the country of Natal, a small cloud similar to the Ox's Eye at the Cape, produces the like effects. In the sea between Africa and America, especially near the equator, these kind of tempests very often arise. Near the coast of Guinea, three or four of these storms sometimes happen in a day; they are also caused and announced by small black clouds; the rest of the sky being generally serene, and the sea perfectly calm. The first blast which issues from these clouds is furious, and would sink ships in open sea, if they did not take the precaution to furl the sails. It is principally in April, May, and June these tempests are experienced on the coast of Guinea, because no regular wind blows there. The stormy season on the coasts of Loango is in January, February, March, and April. On the other side of Africa, at Cape of Gardafu, these kinds of tempests rise in May, and the clouds which produce them are generally in the north like those of the Cape of Good Hope.