ARTESIAN WELLS. 



429 



The following table represents the condition of the wells al the time of 

 investigation in December, 1890: 



The flowing wells are located along the Platte bottoms. Manj wells 

 of like location, the collars of which have practically the same altitude, 

 were not flowing, being heavily pumped for manufacturing purposes; had 

 this demand lessened it is probable that the water-level along this portion 

 of the held would have risen considerably and many wells then falling 

 below the surface would have again flowed. 



I Al'.sl - ' >l I'F.IIIH.M: IN I I.' >\\ s. 



The causes of decrease in how and of the total failure of so many 



wells are mainly three: First, ] r casing and packingj second, filling or 



cloereing with sand: third, tapping' of the same water-bearing 1 stratum l>v 

 too many wells. 



Defective casing and packing. IllStallCO of defective Casing alld packing U ClV 



of frequent occurrence in the earlier wells of the Denver field, the result 

 of inexperience. In casing, the chief fault lay in the selection of unsuitable 

 material, even stovepipe at one time being used in some of the wells. 



Of the packing employed in the Denver Basin, the device of the seed 

 bag is the most common, but shot, cement, leather, rubber, and a compo- 

 sition ot' sand, iron filings, and sal ammoniac have not infrequently been 

 used. The fault in packing lay almost wholly in the improper preparation 

 of the material and in placing it in the bore. 



clogging. — A typical illustration of this is found in one of the Denver 

 and Rio Grande wells. No. 50 of the series. After a steady decrease in flow 

 for six months the well was examined and found to have filled with sand 



