WIND.
Bars, . . . . HIND. I Vaya, . . . . SANHIC. Ang, MALAY. Gel, Tax bad, PERfi.
In 1831, Mr. Redfield of New York established the fact that storms, seemingly the most violent and lawless, moved with precision in fixed paths, and executed their rotative movements with almost the regularity of the balance-wheel. Ile also demonstrated that hurricanes in the northeni hemisphere revolve around their centre iuvariably in a direction contrary t,o that of the hands of a watch, aud the knowledge of this physical law of storms, in countless cases has saved large vessels, and even whole squadrons, from pro bable destruction. Captain Douglas Wales of tho Mauritius, a sailor of experience and great practical knowledge and skill, in a paper on the Couvergiug of the Wind in Cyclones, argues that on the margin of these storms, whose diameter is often several hundred miles, the wind does not always blow around the ceutral area of the storm in concentric circles, but fre quently it converges or curves inward, in nearly radial lines, upon the centre of the gale. AS iL is in the ceutre that the verticose motion of the cycloue is most intense and deadly, it is of course of the first importance to give it a wide berth. According to the law of storms,' m first otated by Messrs. Redfield, Reid, Dove, and others, tho winds within tha entire area of atinospheria dis turbance blew in perfect aud conceutric circles around the common centre. Captain Wales, how ever, after multiplied observations, shows that this rule is not strictly observed by the winds. This importaut fact does not, however, at all overthrow, but confirms Mr. Redfield's disoovery. The converging of the wind towarda the centre of tha revolviug gale, is of course due to tho centri petal force beiug gre.ater than the tangential force, which is the fact observed in tornadoes.
Dust storms of India sweep along the surface cf the ground sometimes for two or three hundred miles, and cause much inconvenience.
Land and sea breezes occur on the seaboard of all tropical countries, and on all islands in the tropics. Upon the northern coast of Java, the phenomenon of daily land and sea breezes is finely developed. There, as the sun rises ahnost per pendicularly from the sea with fiery ardour, in a cloudless sky, it is greeted by the volcanoes with ft column of white smoke, which, ascending from the conical summits high in the firmament above, forms a crown, or assumes the shape of an immense bouquet that they seem to offer to the dawn ; then the joyful sea breeze plays over the flood, which, in the torrid zone, furnishes with its fresh breath so much enjoyment to the inhabitants of that sultry belt of earth, for by means of it everything is refreshed and beautiful. The trans
parency of the atmosphere is so great there that they can sometimes discover Venus in the sky in the middle of the day. In the rainy season the land looms very greatly, and mountains which are from 5000 to 6000 feet high are visible at a distance of 80 or 100 English miles.
In the 1?ed Sea the wind from May to November is northerly, and the other six months is southerly, but there are also land and sea breezes.
Monsoons, Trade-Winds.—Mountains which lie athwart the course of the winds have a dry and rainy side, and the prevailing winds of the lati tude determine which is the rainy and which the dry side. The weather side of all such mountains as the Andes is the wet side, and the lee side the dry. Were the Andes stretched along the eastern instead of the western coast of America, we should have an amount of precipitation on their eastern slopes that would be truly astonishing ; for the water which the Amazon and the other majestic streams of South America return to the ocean, would still be precipitated between the sea-shore and the crest of these mountains.
The same phenomenon, from a like cause, is repeated on the mountain sides in inter tropical India, only in India each side of the mountain is made alternately the wet and the dry side by a change in the prevailing direction of the wind. From October to April the north east trades prevail. They evaporate from the Bay of Bengal water enough to feed with rain during this season the western shores of this bay. After the north-east trades have blown out their season, which in India ends in April, the great arid plains of Central Asia, of Tartary, Tibet, and Mongolia become heated up ; they rarefy the air of the north-east trades, and cause it to ascend. This rarefaction and ascent, by their demand for an indraught, are felt by the air which the south east trade-winds bring to the equatorial doldrums of the Indian Ocean ; it rushes over into the northern hemisphere to supply the upward draught from the heated plains, as the south-west mon soons. The forces of diurnal rotation assist to give these winds their westing. Thus the south east trades in certain parts of the Indian Ocean are converted during the sunatner and early autumn into south-west monsoons. These come from the Indian Ocean and Sea of Arabia loaded with moisture, and, striking with it perpendicularly upon the ghats, precipitate upon that narrow strip of land between this range and the Arabian Sea an amount of water that is truly astonishing.