372 SAND-SPOUTS IN THE MONGOLIAN DESERT. 



says, to believe this had been transported from the pine 

 forests lying at least 400 miles to the South. f 



Here we must cut short this digression on certain 

 scientific aspects of " dust, " the object of which, we 

 need hardly say, has been to impress upon the reader 

 the extraordinary and apparently illimitable capacity pos- 

 sessed by the atmosphere, both in calm and in storm, and 

 whether in a clear, or in a misty state, of carrying par- 

 ticles of organic and inorganic matter to great distances. 



The "red fog" which we have alluded to above,, 

 probably implies a condition of the atmosphere satur- 

 ated with dust, carried by the wind from the desert. 

 In these great sand storms, the wind in the desert 

 generally veers about in an extraordinary way, and 

 cross currents, proceeding from opposite directions, 

 meet, and drive against each other, from perhaps two 

 or three different quarters at once and in this way 

 the whirlwinds or sand-spouts are produced. In the 

 vortex formed by the meeting of these opposing squalls 

 the wind would naturally gyrate with extreme violence 

 and rapidity, raising up, at each point where this 

 occurs, those tortuous columns of sand and dust, so 

 frequently described by travellers as " waltzing " across 

 the surface of the desert. 



Mr. Atkinson states, that when traversing the Mon- 

 golian Desert, 



"In the middle of a space sown with innumerable hillocks, 

 of sand, we saw about thirty of them suddenly raise them- 

 selves around us, lengthen into long elliptical columns, and 

 sweep over the surface of the desert with the hissings and 

 contortions of gigantic serpents. These spouts varied in 



* The Effects of Cross and Self -Fertilization in the Vegetable Kingdom^. 

 by Charles Darwin, 2nd Edit. 1888, p. 405. 



