356 DESERT SAND STORMS. 



painful and possibly even dangerous to respire it the dust 

 on these occasions being of so fine and penetrating a 

 nature, that it makes its way everywhere, and through 

 every sort of covering, no matter what precautions 

 may have been taken to exclude it and is of course 

 very prejudicial to the works of watches, and other 

 delicate instruments, including breech actions, and locks 

 of guns, etc. * Watches therefore should be wrapped 

 up in wash-leather bags. 



In some of the great deserts, these storms frequently 

 take the form of whirlwinds, and columns of sand 

 and dust appear gyrating across the plain in a most 

 threatening way, apparently menacing passing caravans 

 with destruction. Many stories are related by the 

 Arab historians of instances in which whole caravans, 

 and even armies, have been suddenly overwhelmed by 

 these storms, and buried in the sand. 



In these incredulous days, however, these histories 

 have come to be regarded as exaggerations, and there 

 can be no doubt that this modern view of the case 

 is substantially correct these calamities, when they 

 have occurred, being probably due to thirst, and not 

 to sand storms, although the partially buried corpses, 

 subsequently found more or less covered by the sand 

 drift, may at first sight appear to furnish strong corro- 

 borative evidence of their destruction by a whirlwind. 



The destruction of the army of the Persian Monarch 

 Cambyses (B.C. 524) f which perished in the Libyan 



* In the dry plains of South Africa where cold winds and dust storms, 

 are prevalent, experience shows, that " pneumonia " or acute inflammation 

 of the lungs is a thing always to be dreaded. At Johannesburg and 

 other places in the Transvaal in winter it is sometimes exceedingly fatal* 

 acute cases proceeding to a fatal issue in the course of a few hours. 



f The History of the World, by Philip Smith, Vol. i., p. 286. 



