396 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 



as the traveller approaches, and at last entirely disappears 

 when he is on the spot." Belzoni's Narrative, pp. 341- 

 343, and p. 196. This description substantially coincides 

 with that of Quintus Curtius, who, in detailing the 

 passage of Alexander the Great and his army through 

 the deserts of Sogdiana, says : " Amidst a dearth of 

 water, despair of obtaining any created thirst before it 

 was excited by nature. Throughout four hundred stadia 

 not a drop of water springs. As soon as the summer 

 heat pervades the sand everything is dried up as in a 

 burning kiln. Steaming from the fervid expanse, which 

 appears like a surface of sea, a cloudy vapour darkens the 

 day," &c. Quint. Curt., lib. vii. c. 5. The phenomenon 

 described by these writers is supposed to be produced by 

 a decrease in the density of the stratum of the atmosphere 

 in immediate contact with the ground, arising from the 

 intense heat of the sun upon the sand; but there is 

 probably also a small amount of vapour or steam at the 

 high temperature of invisibility along with it, and which 

 would in that state rather increase the inconvenience 

 of the traveller, and even aid to blister his skin, as 

 Curtius further remarks, than modify the heat and 

 drought, or help him ; for more recent travellers seem to 

 indicate from their observations that there is water at no 

 very great depth below the sand. And, indeed, it is a 

 remarkable fact that the Arabs, with the well-remembered 

 examples of the patriarchs before them, whose Artesian 

 works remain, and are pointed out by them to this day, 

 should not have dug wells at convenient distances for 

 their caravan journeys, and established caravansaries 

 at them, to prevent the horrors Belzoni has described, 

 and with the fatal features of which they have had grim 

 familiarity down through all the ages of their history. 

 The desire for short routes and railway communication 

 will probably come to their aid at last, and accomplish 



