Science as yet has not been able to grasp the laws that govern cyclones. They seem to be the result of some intensely electric condition of the elements, which finds an expression in that form. Cyclones, until within a few years, meant those circular tempests encountered in the Pacific and Indian oceans. They are the most destructive of all storms, being far more deadly than monsoons and tornadoes.
All navigators, when caught in a cyclone know how to get out of it. They have only to sail at right angles to the wind, when they will either pass beyond the outer rim of the circular sweep, or reach the center, where the ocean is calm.
The diameters of the ocean cyclones range from fifty to five hundred or a thousand miles. Professor Douglas, of Ann Arbor University, entertains his friends now and then by manufacturing miniature cyclones. He first suspends a large copper plate by silken cords. The plate is heavily charged with electricity, which hangs below in a bag-like mass. He uses arsenious acid gas, which gives the electricity a greenish tint. That mass of electricity becomes a perfect little cyclone. It is funnel-shaped and spins around like a top. When he moves the plate over a table, his cyclone catches up pennies, pens, pith balls and other small articles, and scatters them in every direction.
Cyclones never touch the equator, though the ocean ones are rare outside the torrid one. They are caused by the meeting of contrary currents of winds, and are known under the names of hurricanes, typhoons, whirlwinds or tornadoes. Those terrifying outbursts which now and then cause so much destruction in our own country seem to be the concentration of the prodigious force of an immense ocean cyclone within a small space, which renders them resistless.
A writer in the N. Y. Herald gives some interesting facts regarding these scourges of the air. While the cyclone, as we have shown, may have a diameter of hundreds of miles, the track of a tornado is often limited to a few hundred feet, and rarely has the width of half a mile.
The cyclone carries with it a velocity of as much as 100 to 140 miles an hour. It sends a certain amount of warning ahead of its track, and the acceleration of the wind's speed at any given point, is gradual.
The tornado falls almost without notice, or rather the indications are often so similar to those of an ordinary thunderstorm that only a skilled and careful observer can detect the difference.
The phenomena and effects of cyclones in the West Indies have long been subjects of study and observation. As the center approaches a ship she is assaulted by wind of a terrible force and a sea that is almost indescribable. The water no longer runs in waves of regular onward motion, but leaps up in pyramids and peaks. The wind swirls and strikes until wherever there is a chance for vibration or flutter, even in tightly furled sails, the fabric soon gives way. I once saw a brig go drifting past us in a West Indies cyclone with everything furled and closely lashed with sea gaskets. We were in company nearly at the height of the storm, when the center was only a few miles away. There was a spot in the bunt of the foretopsail where the sail was not tightly stowed, and for several hours it had doubtless been fluttering under tremendous pressure. As I watched her a little white puff went out of the bunt of the topsail, and then the destruction of the sail was rapid. Long ribbons of canvas went slithering off as if a huge file had rasped the yard arm, and in a short time there was nothing left on the yard except the bolt ropes and the reef tackles. We could do nothing to help the crew, for it was doubtful whether we could keep off the reefs ourselves, and the brig passed out of sight to her certain doom.
The local tornado that so frequently plays havoc with property and life in the West is, like the cyclone, a revolving force, but it carries with it a variety of phenomena wholly distinct from those that accompany the larger storm. Many of the effects of one tornado are wholly absent in others, and the indications that in one case have been followed by a terrible disaster are not infrequently found at other times to presage merely a heavy thunder shower.
The freaks of a tornado are wholly unaccountable. In some cases not an object in its track will fail to feel its power for long distances; in other instances it will seem to act like a cannon-ball that plows up the earth on striking, then rises and strikes again, leaving the space between untouched. Sometimes it will go through a forest leveling the trees as though a gang of axemen had plied their tools on lines laid out by surveyors, nothing outside the track being touched; but again in similar windfalls there will be found occasional pockets scored in the forest growth jutting off the right line, like small lagoons opening into a flowing stream. These seem to have been caused by a sort of attendant whirlwind—a baby offspring from the main monster, which, having sprung away from the chief disturbance, scoops a hole in the woods and then expires or rejoins the original movement.
I have seen one of the most violent and, so to speak, compressed of these storms, cut a road through thick woods so that at a distance the edges stood out clear and sharp against the sky as would those of a railway cutting through earth. Trees standing at the edge ............