All continents are subject to variable winds, which often produce singular effects; in the kingdom of Cassimir, which is surrounded by the mountain of Caucasus, at the mountain Pirepinjale, extraordinary and sudden changes are experienced; we pass, in less than an hour's travelling, from summer to winter; at this place are two winds, a north and south, and which, according to Bernier, we successively feel in less than 200 feet distance from each other; the position of this mountain must be singular, and merit observation. In the peninsula of India, which is crossed from north to south by the mountains of Gate, it is winter on one side, and summer on the other at the same time. The like difference is met with on the two sides of Rozalgate Cape in Arabia; the sea to the north of the cape is perfectly tranquil, while in the south violent tempests are experienced. It is the same in the island of Ceylon; winter and high winds are experienced in the northern parts of the island, while in the southern there is fine summer weather. This contrariety of seasons at the same time not only happens in many parts of the Indian continent, but also in many islands; for example, at Cerem, a long island in the vicinage of Amboyna, they have winter in the northern part, and summer at the same time in the southern, and the interval that divides the two seasons is not above three or four leagues.
In Egypt they have a south wind in summer, so hot as to prevent respiration, and raises such great quantities of sand, that the sky seems covered with thick clouds; this sand is so fine, and driven with such force, that it penetrates even into the closest chests. When these winds last many days they cause epidemical diseases, which are often followed by a great mortality. It seldom rains in Egypt, nevertheless every year there are some days of rain in the months of December, January, and February. Thick mists are more frequent there than rain, especially in the environs of Cairo; these mists begin in November, and continue all the winter; and during the whole year there falls so plentiful a dew, even when the sky is serene, that it might be taken for a slight rain.
In Persia winter begins in November and lasts till March: the cold is intense enough to form ice: much snow falls on the mountains, and often a little in the plains. From March to May the winds blows with great violence, and bring heat with them. From May to September, the sky is serene, and the heat moderated by fresh breezes, which rise every evening and remain till morning. In autumn they have violent winds, like those of the spring; nevertheless, although these winds are very violent they scarcely ever produce tempests or hurricanes; but in summer there often arises along the Persian Gulph a very dangerous wind, called by the natives Samuel; it is still hotter and more terrible than that of Egypt. This wind is mortal, and acting like an inflamed vapour, it suffocates every person unfortunately enveloped within its vortex. In summer there also rises a wind of the same kind along the Red Sea, which suffocates men and cattle, and which conveys so great a quantity of sand that many persons conceive this sea will in time be choaked up with what falls therein. There are often clouds of sand in Arabia which darken the air and form dangerous whirlwinds. At Veru Cruz, when the hot north winds blow, the houses of the town are almost buried under the sand. In summer hot winds rise also at Negapatam, in the peninsula of India, likewise at Petapouli and Masulapatan. These burning winds, which destroy people, are fortunately of short duration, but they are very violent, and the greater swiftness they come with the more dreadful are their heats, whereas all other winds refresh so much the more as their velocity is greater. This difference proceeds from the degree of heat in the air, for while the heat of the air is not so great as that of the body of animals, the motion of the air is refreshing; but if the heat of the air exceeds that of the body, then its motion heats and burns. At Goa the winter, or rather the rainy and tempestuous season, is May, June, and July, and without which rains the heat would be perfectly unsupportable in that country.
The Cape of Good Hope is famous for its tempests, and the singular cloud which produces them. This cloud appears at first like a small round spot in the sky, called by the sailors the Ox's Eye. Probably its appearing so minute is owing to its exceeding great height.
Of all travellers who have spoken of this cloud, Kolbe appears to have the most examined it with attention; his words are, "The cloud seen on the mountains of the Table, or of the Devil, or of the Wind, is composed, if I am not deceived, of an infinity of small particles, impelled first against the mountains of the Cape towards the east, by the easterly wind which blows during almost the whole year in the torrid zone; these particles are stopt in their course by these high mountains, and collect on their eastern side; they then become visible and form these assemblages of clouds, which being incessantly driven by the east wind, rise to the summit of these mountains; they do not long remain there at rest, but being obliged to advance, they ingulph themselves between the hills before them, where they are bound and confined as in a canal; the wind presses them from above, and the opposite sides of the two mountains retain them in a direct line: in advancing they arrive at the foot of a mountain, where the country is a little more open, they then expand, and become again invisible; but they are shortly driven against other mountains, by clouds which are behind them, and thus proceed with much impetuosity, until they arrive at the highest mountains of the Cape, which are those of the Wind, or Table, where they have to encounter a wind blowing in an exact contrary direction; this occasions a dreadful conflict, for the vapours being impelled behind and repelled before, produce horrible whirlwinds either on the high mountains of the Table, or adjacent vallies. When the north-west wind yields, the south-east increases and continues to blow with more or less violence for six months, it reinforces itself while the cloud of the Ox's Eye is thick, because the vapours collected behind press forward, and it diminishes as soon as its thickness is lessened, because there are fewer particles and less pressure, and it is entirely lowered when the Ox's Eye is no longer apparent, because no new or not sufficient vapours any longer come from the east.
"All the circumstances attending this phenomenon lead to an hypothesis, which well explains every part of them: First, behind the mountain of the Table we remark a train of light white mists, which commencing on the eastern descent of this mountain, incline to the sea, and occupy the mountains of Stone throughout all their extent; I have often contemplated this train, which according to my opinion was caused by the rapid passage of the vapour above-mentioned, from the mountains of Stone to that of the Table.
"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."