TflE FARM WATER SUPPLY 



11 



Water from very deep wells which get their supply from 

 strata of soil below the influence of local surface impurities, 

 usually difler somewhat in composition from the waters of un- 

 polluted springs, more particularly in the amounts of mineral 

 matter and chlorine. In the table which includes a few such 

 wells, it will be noticed that the solid residue is much higher 

 in proportion, than it is in the spring- waters ; yet the insolu- 

 bility of our granite rocks is still manifest, because similar 

 depths in other parts of our country yield water containing 

 from four to ten times as much soluble mineral matter. 



CONSTITUENTS OF WATERS FROM DEEP WELLS. PARTS IN 100,000. 



* Solid residue contained much lime. 



t Solid residue contained much iron. Water was opalescent with iron com- 

 pounds. 



* Well dug through 5 feet of sand, then through 28 feet of soft clay. Thence 

 an iron pipe ( riven down 59 feet, finally striking a thin layer of gravel over 

 solid rock. Bottom of pipe reaches a depth 15 feet below the bed of the river, 

 which at high tide runs within 50 feet of the well. Well overflows continuously 

 at a level 5 feet above high tide. 



5 Well 108 feet in depth, first 30 feet in sand, then 68 feet in clay, remainder in 

 gravel. Water rises to within 10 feet of surface of ground. 



'■Well 170 feet in depth, drilled down from the bottom of an old well through 

 140 feet of rock. 



"Well 128 feet in depth, drilled in a ledge. 



A few samples of water have been received that were seri- 

 ously contaminated with iron, though otherwise good. Such 

 water is usually clear when freshly drawn from the well, but 

 on exposure to the air, it soon becomes opalescent, due to the 

 changes taking place in the iron salts by which insoluble com- 

 pounds are formed, sometimes ending in deposits of particles 

 of iron rust. vSuch water is more unpleasant than injurious, 

 being especially unsuitable for laundry use. The iron may, 

 and usually does', come from iron salts in the rocks ; but in one 

 case it appeared to be due to an old chain-pump. The former 

 cases cannot be remedied, but the latter could be. 



