CHAPTER XIII. 



DRIVEN AND JEI WELLS. 



Extensive Use of Driven Wells. Driven wells, which are 

 sunk by forcing iron pipes, equipped with points (Fig. 36, 4) at the 

 end, into the ground by blows at the top of the pipe, are exceed- 

 ingly common in the United States as well as in other parts of the 

 world. They are found in the sand and gravel terraces along our 

 principal rivers, in the sandy and gravelly glacial deposits, through- 

 out the great area of soft sediments along the Atlantic and Gulf 

 coasts and Mississippi Valley, and elsewhere. Abroad, they have 

 been used in army camps at many points, being frequently known 

 as Abyssinia wells because of their extensive use in the Abyssinian 

 campaign of 1895. 



Advantages and Disadvantages of Driven Wells. From the 

 fact that they may be quickly sunk, that they are relatively 

 cheap and that the tight casings, carried to or below the water 

 level, shut out polluting matter, it follows that the popularity of 

 these wells is deserved. They possess, of necessity, however, cer- 

 tain drawbacks. These are indicated, together with their merits 

 in the following table. 



Driven wells. 



Advantages. 



Disadvantages. 



Ease of construction; often sunk in a few hours; 



only hand or horse power usually required. 

 Outfit is inexpensive, can be quickly put up, and 



does not require skilled labor. 

 Tubing is readily obtainable and inexpensive. 

 Cheapness. 



Safety; can be located near sources of pollution if 

 sunk through impervious bed preventing access 

 of contaminating matter to water bed; nothing 

 can enter at top. 



Permanency of supply as compared with dug 

 wells. 



Cleaning seldom necessary as compared to open 

 wells. 



Limitation to soft materials. 

 Utilization of a single water stratum. 



Usual limitation to moderate depths. 



Restriction to open porous water beds due to absence of 



storage facilities. 



Slow response to rainfall as compared to many dug wells. 

 Corrosion of pipes or screens. 

 Incrustation of pipes and screens. 



Entrance of quicksand through screens. 



Taste of water due to solution of the iron under certain 



conditions. 



Difficulty of cleaning in case of clogging. 

 Short life as compared to some dug wells. 

 Absence of information as to minor water beds or materials 



penetrated. 



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