National Geographic : 1897 Mar
STORMS AND WEATHER FORECASTS the storm, which places the center inland, so that the whole eddy can be charted. West India hurricanes are cyclonic in character, but on account of the fact that the diameter of the whirling eddy is much less and the velocity of rotation much greater than in the average cyclone, it is customary to designate them as hurricanes. In other words, the hurricane is a cyclone of small area but of powerful vortical action, and consequently of great destructive force. To get a rough idea of the difference between storms, we might classify them according to the diameter of the revolving mass of air under their influence as follows: Cyclones, 1,000 to 2,000 miles; hurricanes, 200 to 500 miles, and tornadoes one-half mile to one mile. Then if a great quan tity of heat energy is liberated by profuse condensation of aque ous vapor near the storm centers, we might imagine their vortical action and their destructive force to increase as their diameters of rotation decrease. Charts XX to XXV show the progress, in twelve-hour inter vals, of the hurricane northeastward to New England. It will probably leave the American continent at Nova Scotia and in three or four days cross the Atlantic and make its appearance on the northwest coast of Europe. Twenty-five years ago mariners depended on their own weather lore to warn them of coming storms; then, although the num ber of boats plying the seas was much less than it is now, every severe storm that swept across them left death and destruc tion in its wake, and for days afterward the dead were cast up by the subsiding waters and the shores were lined with wreckage. Happily this is not now the case; the angry waters and the howling winds vent their fury the one upon the other, while the great mass of shipping, so long the prey of the winds and waves, rides safely at anchor in convenient harbors. The United States has the most extensive weather service in the world, and its enormous practical utility is now universally recognized. Careful estimates based on reports from interested parties indicate that cold-wave signals effectively displayed in advance of one severe cold wave sweeping across our country re sult in a saving of over $3,500,000, while responsible marine representatives declare that each West India hurricane passing up the Atlantic seaboard would destroy not less than $2,000,000 worth of property and many lives if danger signals were not dis played well in advance of its coming.