SCENE AT OLNEY, ILL.
Let one observe a great fire in a forest or prairie. On the outskirts of newly burned areas, when the air has been rarefied by heat, may be seen sudden and violent movements about a point, as though there was a spirit in the wind. In a moment it has lifted the ashes and scorched
WHIRLWIND FROM BURNT PRAIRIE.
stalks, and whatever light matters were in its way, and circling, perhaps, wider and stronger for a time, has borne them onward and upward toward the heavens, where at length its force was dissipated, and it mingled with the surrounding air. Similar movements were excited along the southern limits of the storm area, which we are describing; and hence, not one cyclone, but more properly speaking, a multitude of little cyclones—tornadoes independent of each other, but dependent on the main current, or great eastward traveling storm center—swept through points in Illinois, Missouri, Tennessee and Kentucky; all rushing toward the line of the lowest barometrical depression, the actual and advancing storm center. Not since the Signal Service had been established had the barometer at St. Louis stood so low as 28.46, which, reduced to sea-level, means 29.08. Toward this region of rarefied air—this partial vacuum—the cyclonic movements from the south rushed with inconceivable fury, and as the nucleus of the storm was rapidly moving eastward, the cyclonic movements were turned from a north to a northeast course. All these varied movements simply result from the effort of a disturbed atmosphere to restore an equilibrium.