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About The west shore. (Portland, Or.) 1875-1891 | View Entire Issue (July 1, 1886)
218 THE WEST SHORE. THE) BALMY CHINOOK. rplIE warm Pacific wind which penetrates inland I ncroHH Oregon, Washington and DritiHh Columbia -L to the valleys tit Idaho, Montann and the Ciuia dian territories, molting the biiow and keeping the cattle ranges clear for stock to graze the entire winter, is known throughout thin whole region as the " Chinook." It follows the mountain posses in it journey inland, and consequently is in some localities a south wind, in others a north wind, and varying from all jxiinU of the com pass went of these. This wind in its relation to the province of Manitoba, was thus recently discussed by Mr. A. Itowennan, 13. A., at a meeting of the Manitoba Historical Society iu Winnipeg: Homo one has said " The climate makes the country." If this proositioii is only measurably true and there seems no doubt uf it there are few questions of greater imjmrtauoe in connection with the capacities and future proHiMH-ts of our laud. It may have been noticed how' readily the citizens of our country, having grown proud of the country, become likewise 'proud of tho climate. It would be counted a strange method to 0en up the question of our climate with a consideration of a phe nomenon occurring a thousand miles west, but our ideas readily adapt themselves to the largeness of our land. " No Kut-up Utica oontraeU our powers; but the whole boundless continent is ours," and wo easily regard the llockiog as only just tho other sido of our horizon. Moreover, it will appear on inquiry, that the Chinook winds are intimately connected with tho whole question of our climate. Those winds are noticed by tho ol (serv er as coming down in tho dead of winter from tho snow oovored mountains so warm and dry as tocauso the total disappearance of tho snow in a few hours. 80 hard is it to credit the evidence of our senses, that tho common description of these winds is that they 001110 through the passes of tho mountains from tho Pacifio a wonder none the less than that which it is supposed to explain. One observer of souio note, indeed, hazards the conjec ture that the warm winds of the (lulf of Mexico reach all the way up north, over tho high plateau of tho great American desert, over the still higher mass of hot and rariflod air overhanging this desert, and drop conveni ently on our lower plains to tho north. But as this writer of deserved repute in his own department man ifestly confounds the lines of equal heat with the direc tion of tho winds, we may ho excused from giving much consideration to his theory. Fortuuately, we liavo suf ficient data of ik strictly reasonable and scientific kind, without indulging in conjecture which, too often, aro the only iuport of theories on climate or the weather. A very brief statement of a few points in physical geo graphy may be necessary as a prelude to tho matter be fore us. OuUtide of the region of trade winds, L e., from thirty to sixty degrees uorth latitude, is a one noted for iU alternate winds; winds from tho southwest alternately with winds from the northeast-the south, vest prevailing. This ia the Imlt of the return trades, or anti-trades. As the trade winds get their direction from the motion of the earth, which glides, as it were, from under the cool winds moving equatorwarda, they re tain the westward motion gained at the equator, and in latitudes not so progressive outstrip the motion of the earth, and thus give rise to southwest winds. But these have not the persistency of the genuine trades of the equatorial regions, and bo merely alternate with the po lar winds from tho northeast Such being the state of things in the wide belt including such a great part of tho continent, we my now take up the local modifying influoucos. Consulting our map, we notice a lofty bar rier along the west coast in fact, a number of success ive ranges of mountains. The point most interesting to us is whore the Coast range is broken by the inlet called the Strait of San Juan. And here let me call attention to the peculiar elbow made by the ranges nearest the ocean, the direction changes from due north to north west, best seen on a globe. Next note that all the ranges are much lower here than further south. The coast range south of forty-nine degrees rises up like a great wall, and the inner ranges are still loftier. Then the valleys of the Frasor and Columbia give unmistakable hints of passages through the mountains, which fur nished a pathway for the winds long ages before the ad vouturous railroad builder threaded his way aoross and through the labyrinth. The southwest winds then blow ing warm from the Japan current, the Gulf streams of the Pacific, brought to a focus, as it were, in this angle of the mountains, crowd onward through the river val leys, over the low ranges, across the sea of mountains of British Columbia, and finally breasting the last great wall of tho Rocky mountains, make thoir final leap into the valley below. Having thus traced their course over the mountains, let us inquire into their adventures in this journey of five hundred miles. On leaving the Pacifio they are warm and heavily laden with moisture. The first range they moot takes toll from thoir burden. Heavy clouds aro formed and rain falls. The process is repeated at each successive range. In higher regions the scanty supply of moisture now becomes snow. Iu lofty alti tudes, almost completely robbed of moisture they be come greatly rarified and very cold. Moisture is gone and heat is gone. Our problom is still unsolved. Lot us now retrace our steps to the coast and examine into the question of heat, for modern science declares that that is never lost any more than any other force of na ture. We Cud that in each condensation, first cloud, thou rain and snow, boat is produced to speak accu rately, latent heat becomes sensible. Rain and snow re main behind, are absolutely lost to the air currents. Not so tho heat; this remains with tho air, and seems to be iucroased. But in tho lofty regions of the moun tains rarefaction takes placo, and this uses up heat It requires heat to produce rarefaction, or disappearance of beat accompanies rarefaction, put it which way you will; the heat is not lost, and when, pouring down the mountain side, the great volume of dry air becomes