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THE NATIONAL GEOGRAPHIC MAGAZINE 



traversing the Erg during the hottest 

 season of the year, when the wind was 

 blowing constantly from the south, our 

 caravan, worn out by the whirlwinds of 

 sand which darkened the atmosphere and 

 prevented the guides from leading the 

 way, had to stop several times." 



The most terrible form of the desert 

 storm is the simoon, "the poison wind." 

 As it approaches the observer its front 

 extends at least from 5 to 20 miles, very 

 much like the advancing front of a series 

 of thunder-storms on a hot afternoon ; 

 the clouds of fine sand and dust that are 

 carried up by the wind extend as a haze 

 overspreading the sky ; the heavier sands 

 are also transported in large quantities, 

 and as they fall are collected in mounds 

 around every obstacle like the drifts of 

 snow in winter. In the case of an ex- 

 tended simoon the finer sands are carried 

 so high as to be drawn into the general 

 circulation over Europe. Thus in the 

 great storm of March 10-12, 1901, red 

 and yellow sand and dust from the Sa- 

 hara fell in nearly every portion of Ger- 

 many, France, Austria, and Turkey, and 

 southward over the Mediterranean, and 

 was also reported in southern England 

 for the first time on record. 



In his explorations amid the sand 

 dunes of Asia, Sven Hedin encountered 

 many furious sand storms.* 



"For it drove right into my face with 

 terrific violence, smothering me with 

 sand and fine reddish yellow powdery 

 dust. I could not see a single glimpse 

 of the caravan. It was like wading 

 against running water or liquid mud, and 

 despite my most desperate efforts I was 

 unable to make headway. My previous 

 footprints were entirely obliterated — ob- 

 scured the instant I lifted my foot. . . . 



"The camels knelt in a long row, with 

 their necks stretched out flat on the 

 ground in the direction in which the tem- 

 pest was blowing. Close to the earth 

 the wind had a velocity of 40^ miles 



*From "Central Asia and Tibet," Sven 

 Hedin. Charles Scribner's Sons. 



an hour; but on the top of an adjacent 

 mound, only 6 or 7 feet high, it was 

 some 18 miles an hour more, or 58^2 

 miles in all, and I was only able to keep 

 my balance when I knelt. The storm 

 came from the northeast, and its vio- 

 lence enabled me to form some idea of 

 the inconceivable quantities of sand and 

 dust which are transported by this 

 mighty agent. When we stooped down 

 we were well nigh choked by the swirl- 

 ing cloud, which careered along the 

 ground like a cataract, making little 

 eddies of dust as k swept on. Branches, 

 tufts of grass, grains of sand as big as 

 peas were whirled into our faces w r ith 

 stinging force. . . . 



"Only those who have been out in 

 such a storm can form any conception of 

 what it is like. You get bewildered and 

 want to keep going, without knowing 

 where. Your sense of locality is para- 

 lyzed, and although you think you are 

 going in a straight line, you are in reality 

 describing a circle. It is a kind of desert 

 storm sickness, more nearly resembling 

 the panic which seizes a person on the 

 edge of a precipice than seasickness or 

 mountain-sickness, because it affects the 

 brain." 



MAP OF MEXICO. 



A LARGE map of Mexico, 18 by 25 

 finches, and in colors, will be pub- 

 lished as a supplement to the next, 

 number of the National Geographic 

 Magazine. The map gives the railway 

 lines, names of towns and villages, and 

 all the latest geographical information. 

 The elevations of the different parts of 

 Mexico are shown by gradations of color. 



The same number will contain two 

 notable articles on Mexico, "Our Neigh- 

 bor, Mexico," by Mr. John Birkinbine, 

 President of Franklin Institute, Phila- 

 delphia, and formerly President of the 

 American Institute of Mining Engineers ; 

 and "Lower California," by Mr. E. W. 

 Nelson, of the United States Biological 

 Survey. 



