Sometimes these violent blasts occur in the Alps, but from a very different cause. Avalanches of great extent often take place on the sides of the mountains, when a vast amount of material, equal to three or four hundred million cubic feet of earth, will fall several thousand feet. Often an avalanche of this kind will produce a wind, which is confined, of course, to a restricted area, that is said to be so violent as to tear one's clothes into shreds. This is not caused by any difference of temperature, but by a violent compression.
There is a peculiar wind that occurs in Switzerland, often, between the months of November and March. These winds last from two to three days and are of great violence--especially near the mountains. They are warm and dry and are caused by an area of low barometer and an ascending current of air occurring at some point north of the Alps, which causes the air from Italy to flow over the Alpine range, causing a tremendous precipitation of snow and rain, which not only takes the moisture from the air, but sets free in the form of heat the energy that was stored in the process of evaporation, and this, together with the compression of the air as it flows down the slope of the mountains, makes it hot and dry. This wind is called the "Fohn."
There is a similar condition of things existing on the eastern slope of the Rocky Mountains which has a modifying effect upon the climate of parts of Colorado, Wyoming, Montana, also extending up into British America. This wind, which is here called "chinook," arises from causes similar to those that are active in Switzerland that give rise to the "fohn" wind.
There is a wind called the "blizzard" that is felt most keenly in Montana and the Dakotas during the winter, which is exceedingly cold and lasts sometimes for a period of 100 hours. The temperature falls at times 30 or 40 degrees below zero and the wind maintains a velocity of from forty to fifty miles an hour. These winds spread eastward as far as Illinois, but not with the same severity, and they move southward to the Gulf of Mexico, spreading over the States of Texas and Louisiana, and are there called "northers." It is exceedingly dangerous to be caught in a blizzard in the Dakotas, where the wind reaches its greatest velocity and the cold its lowest temperature--especially when the wind is accompanied, as it frequently is, by severe snowing. By the time it reaches the Gulf States it is very much modified as to temperature, but it is a very disagreeable wind in that portion of the country, because of the exceeding dampness of the air. One would be much more comfortable in dry, still air, even if it were many degrees below zero, than in an air freighted with moisture, although the temperature has not fallen to the freezing point.