To illustrate, take the great cyclone of August 16th to 22nd, 1888. This started off Point Jupiter, Florida, with a rainfall of 2.2 inches in twelve hours, while the rotary velocity of the wind was sixty miles per hour. Its path across the Gulf of Mexico was a perfect semi-parabola, curving northward into western Louisiana; but rapid as was the rotary velocity, three and a half days were required for the journey across the gulf. Meanwhile, it was rapidly widening: for within a few hours of its reaching land, its eastern edge was assailing Mobile, Alabama, with a south wind of fifty-five miles an hour. Almost at the same time the western half was flooding Memphis and Vicksburg with an enormous rainfall--almost four inches in twelve hours, at Memphis. By the morning of August 21st, thirty-six hours after reaching land, it was central over middle Tennessee and Kentucky; heavy rains fell over the entire region. But by this time its eastern edge was in collision with the Appalachian chain; while a heavy local rain at the northern extremity of that chain created an additional diversion in a new area of low barometer. So it left the hitherto parabolic route, and shot away nearly at a tangent along the western Appalachian slope, passing from Tennessee to Newfoundland in thirty-six hours, thus moving nearly three times as rapidly as in the Gulf: while its violence, or rotary speed, was vastly lessened. This storm was one of the most destructive of the recent cyclones that have swept our country, doing immense damage to crops, bridges, houses, herds--in short, everything that can be seriously damaged by wind or flood. The damage in Louisiana alone was estimated at $500,000. But it was by no means the most destructive of the West India storms. An examination of the areas of calms, which are the hot-beds of cyclones and hurricanes, shows that the region which produces the great cyclones of the United States lies in the Antilles and Caribbean Sea. In the Pacific the portion of the calm belt of the Tropic of Cancer causes the ravages of cyclones or hurricanes originating there to be felt chiefly in Japan and China. The storms of the Pacific arising in the equatorial calm belt, are most violent in the East Indies, and the southern peninsulas of Asia. As these regions are much warmer, and consequently the atmosphere may hold a much greater quantity of vapor, it follows that cyclones in that quarter much exceed in violence those of our own land. Such are the general laws of these terrible disturbances of nature, as ascertained by years of careful observation. In the United States, our Signal Service, with well-equipped observatories at important localities, is able to make these principles of practical use: to detect the incipient storm and mark out its path, ere it strikes its fiercest blow.