532 THE POPULAR SCIENCE MONTHLY. 



opening of the valleys." Also : " Up to 1856, on the left bank of the 

 Ouadi Titersin, there had been a line of downs called Arekka-n-Bodelka 

 so high that camels had been unable to cross them. A freshet in 

 the Ouadi came with such force as to sweep away the entire mass com- 

 posing the downs." 



As M. Duveyrier says, the alluvial deposits from the Saharan tor- 

 rents are often extremely fertile. At Biskra, at the time of the French 

 occupation of that place (1844), a layer two yards in thickness of a 

 rich loam was found on an ancient pillar of Roman construction. 



The existence of subterranean sheets of water being well demon- 

 strated, and a rude example being set by the untaught natives, it only 

 remained to follow that example on the grander scale made possible 

 by the advancement of science, and determine what benefits could be 

 derived from these hidden treasures. Dr. Maurin enunciated, "Dig 

 an artesian well in the region of sands, and the sands will become 

 fixed by vegetation, and a forest of palms will soon stand where there 

 had been a moving plain." And his saying is well borne out by nu- 

 merous facts. In 1872 an old marabout (Mussulman devotee or saint) 

 dug a well, planted palm-trees, and established himself at a place now 

 called Tendouf ; in less than a year it had become an important com- 

 mercial center ! 



The first attempt at boring an artesian well on Algerian soil was in 

 the plain of Oran, on the 7th of December, 1844. It was fruitless, 

 although carried to a depth of 322 feet. A second attempt was made 

 on the 14th of May, 1845, at Arzeu, and was likewise given up at 580 

 feet. Some time after the occupation of Biskra, a boring was made 

 there to 270 feet : no result. It seemed a hopeless task to find living 

 water, although it was well known that many years before the Arabs 

 had had artesian wells. 



General Desvaux, however, commanding the subdivision of Batna, 

 kept studying assiduously to find means of fertilizing the barren re- 

 gions around him. The perusal of several works by Tournel, by Ber- 

 brugger, by Prax, as well as a memoir of M. Dubocq published in 

 1853, convinced him that boring was destined to play an important 

 part in the solution of the problem that so occupied him. In 1854 he 

 chanced to be on the summit of a sand-hill near his camp, and over- 

 looking the entire oasis of Sidi Rached. He saw that luxuriant vege- 

 tation, and turning away was confronted by the sterile waste on the 

 other side. More than ever struck by the contrast, he sent for the 

 sheik and questioned him, and learned that all the northern wells had 

 become filled in with sand, that the parasite waters prevented digging 

 any more, and that the entire population, broken-hearted, were look- 

 ing forward to leaving their homes. As soon as possible he communi- 

 cated with Marshal Randon, Governor-General of Algeria, and was 

 authorized by him to commence a systematic search for water in the 

 Sahara. 



