Whirlwind

an upright whirling column of air. The whirlwind varies from a trifling roadside eddy that lifts one's hat and picks up bits of straw, to a column measuring possibly a half a mile in diameter and extending far into the regions of the clouds above. In either case, the cause is the same. Gusts of air or powerful currents of wind moving in contrary directions meet, and, as they shoulder past each other, they give a twirling motion to an upright column of air formed from their rubbing edges. Of a gusty day numerous small eddies form near the ground. These surface whirlwinds create quite as much amusement as annoyance, but the tornado that prevails between the one-hundredth meridian and the Atlantic is to be dreaded. It is a terrific whirlwind formed in the upper regions by battling currents of cold and warm air. It is a gigantic column of whirling air usually spreading above into the shape of a top. It is so dense that it settles of its own weight, but rebounds like a balloon when it strikes the earth. Seen from a distance, a tornado is a blue-black, funnel-shaped cloud with a long, slender, snaky, twisting, twirling tube descending from its apex. In this region the tornado is formed usually at the close of a sultry day. It approaches from the southwest, traveling across the face of the country in bounds and leaps. Such a storm may be traced, not by a continuous belt of devastation, but by circles or short paths at intervals of a few miles. Here it drops on a group of farm buildings and whirls them about, strewing homes, stock, granaries, horses, household goods, grain, and live stock, and even persons round and round in a circle perhaps half a mile in diameter. Then, leaping over intervening farms, the lashing column dips into a lake and, gathering up water, fish, and boats, drops them in the surrounding woods. At the next leap destruction lands in the midst, it may be, of a thriving town. No building is strong enough to stand. There is a theory that the center of the rotating column is a more or less complete vacuum in which buildings explode from internal air pressure; but, however that may be, in a few seconds of time thousands and thousands of dollars' worth of property are reduced to a shapeless mass of rubbish. The genuine tornado or whirlwind is quite as apt to leap over a high place and settle into a hollow as to do anything else. It travels toward the northeast and rotates in a direction opposite to that of the hands of a watch when laid on a table face upward.

The whirling sandstorm of the Sahara and other regions is a whirlwind that has caught up the sands of the deserts. Camels seek safety by kneeling and stretching out their long necks in the sand, and their drivers lie flat till the whirlwind has passed by. The dangerous squalls and waterspouts encountered at sea are similar columns of air. The water in the wide upper part is from the land. That in the lower part is twisted up from the ocean. Myriads of fish are swept up in this way and not infrequently carried over the land. A waterspout passing at a safe distance, one end in the clouds, the other in the sea, is a magnificent spectacle; but a tornado in an inhabited country is fraught with too great loss of life and property to create any feeling but that of awe and terror.

The United States Weather Bureau applies the term cyclone to a wheel-like rotation extending over a circle, it may be 200 or 300 miles in diameter; to the ordinary observer it is nothing but a change in the direction of the wind.

The whirlwind is a favorite figure in Eastern literature. The Bible is full of references. "Elijah went up by a whirlwind;" "The Lord answered Job out of the whirlwind;" "Destruction cometh as a whirlwind;" Wheels like a "whirlwind;" "The whirlwind of the Lord is gone forth;" "They have sown the wind and they shall reap the whirlwind," are expressions showing that the tornado was well known to the ancients. Shakespeare does put a "whirlwind of passion" into Hamlet's heart, but England is a country of straight-away wind. Dickens, a very master of descriptions of gusts and winds, from the destructive hurricanes that uproot trees and blow off chimney pots to the veriest whisper breathed through keyholes, was unfamiliar with the whirlwind.

See Wind; Typhoon; Simoon; Chinook; Cyclone