We shall now describe a Tornado.—This is a sudden and vehement gust of wind from all points of the compass, and frequent on the coast of Guinea. A tornado seems to partake much of the nature of a whirlwind, or perhaps of a water-spout, but is more violent in its effects. It commences very suddenly: several clouds being previously drawn together, a spout of wind, proceeding from them, strikes the ground, in a round spot of a few rods or perches in diameter, and proceeds thus half a mile or a mile. The proneness of its descent makes it rebound from the earth, throwing such things as are moveable before it, sideways, or in a lateral direction from it. A vapour, mist, or rain, descends with it, by which the path of it is marked with wet.
The following is a description of one which happened a few years since at Leicester, about fifty miles from Boston, in New England: it happened in July, on a hot day, about four o’clock in the afternoon. A few clouds having gathered westward, and coming over-head, a sudden motion of their running together in a point, being observed, immediately a spout of wind struck the west end of a house, and instantly carried it away, with a negro man in it, who was afterwards found dead in its path. Two men and a woman, by the breach of the floor, fell into the cellar; and one man was driven forcibly up into the chimney corner. These were preserved, though much bruised; they were wet with a vapour or mist, as were the remains of the floor, and the whole path of the spout. This wind raised boards, timbers, &c. A joist was found on one end, driven nearly three feet into the ground. The spout probably took it in its elevated state, and drove it forcibly down. The tornado moved with the celerity of a moderate wind, and declined in strength till it entirely ceased.
Harmattan.—This is a name given to a singular wind, which blows periodically from the interior parts of Africa, towards the Atlantic ocean. It prevails in December, January, and February, and is generally accompanied by a fog or haze, that conceals the sun for whole days together. Extreme dryness is the characteristic of this wind: no dew falls during its continuance, which is sometimes for a fortnight or more. The whole vegetable creation is withered, and the grass becomes at once like hay. The natives take the opportunity which this wind gives them, of clearing the land, by setting fire to trees and plants in this their exhausted state. The dryness is so extreme, that household furniture is damaged, and the wainscot of the rooms flies to pieces. The human body is also affected by it, so as to cause the skin to peel off; but in other respects it is deemed salutary to the constitution, by stopping the progress of infection, and curing almost all cutaneous diseases.
We now proceed to some curious particulars, under the term Hurricane.—This is indeed a general name for any violent storm of wind, but is peculiarly applied to those storms which happen in the warmer climates, and which greatly exceed the most violent ones known in this country. Dr. Mosely, in his Treatise on Tropical Diseases, observes, that the ruin and desolation accompanying a hurricane can scarcely be described. Like fire, its resistless force consumes every thing in its track, in the most terrible and rapid manner. It is generally preceded by an awful stillness of the elements, and a closeness and mistiness in the atmosphere, which makes the sun appear red, and the stars larger. But a dreadful reverse succeeds: the sky is suddenly overcast and wild; the sea rises at once from a profound calm into mountains; the wind rages and roars like the noise of cannon; the rain descends in a deluge; a dismal obscurity envelops the earth with darkness; and the superior regions appear rent with lightning and thunder. The earth on these occasions often does, and always seems to tremble; whilst terror and consternation distract all nature: birds are carried from the woods into the ocean; and those whose element is the sea, seek for refuge on land; the frightened animals in the field assemble together, and are almost suffocated by the impetuosity of the wind in searching for shelter, which, when found, is but the prelude to destruction. The roofs of houses are carried to vast distances from their walls, which are beat to the ground, burying their inhabitants under them. Large trees are torn up by the roots, and huge branches shivered off, and driven through the air in every direction with immense velocity. Every tree and shrub that withstands the shock is stripped of its boughs and foliage; plants and grass are laid flat on the earth; and luxuriant spring is changed in a moment to dreary winter. This direful tragedy ended, (when it happens in a town,) the devastation is surveyed with accumulated horror: the harbour is covered with wrecks of boats and vessels; and the shore has not a vestige of its former state remaining. Mounds of rubbish and rafters in one place; heaps of earth and trunks of trees in another; deep gullies from torrents of water; and the dead and dying bodies of men, women, and children, half buried, and scattered about, where streets stood but an hour before,—present the miserable survivors with the shocking conclusion of a spectacle, to be followed by famine, and, when accompanied by an earthquake, by mortal diseases.
Philosophers are now inclined to attribute these terrible phenomena to electricity, though the manner in which it acts in this case is by no means known. It seems probable, indeed, that not only hurricanes, but even the most gentle gales of wind, are produced by the action of the electric fluid.
In the next place we shall treat of Monsoons, or Trade-Winds.
“Trade-winds, observing well their stated course,
To human good employ their pow’rful force;
The loaded ships across the ocean fann’d
By steady gales, spread commerce through the land:
These you observe—but have you no desire
The hidden spring of such effects t’inquire?
Or, when contending winds around you blow,
Do you ne’er wish the cause of them to know?”
Monsoons are those winds which blow six months constantly the same way, and the contrary way the other six months.
Mr. Olinthus Gregory observes, that “though the winds in a temperate zone of the earth are very inconstant and changeable, yet this is not the case in every part of the terrestrial globe; for in the torrid zone, and some other parts, the winds are generally very uniform and constant in their direction, as will appear from the following facts relative thereto:—