Water Lifted By Compressed Air
For Municipal, Manufacturing, Irrigation or Other Water Supply

WATER SUPPLY FOR PUBLIC USE. With the decrease in surface water supply, due to cutting down the forests and meteorological changes, the population has increased enormously, cities have grown together, the country population has become more dense, and the danger of pollution of surface streams oi water has increased a hundred-fold. As the years go on and population and industries multiply, the question will become a’more and more important one. Filtered Water Expensive. Filtration has not proved as successful as some of its enthusiastic promoters had hoped. Such plants usually cost many times over the expense of a good artesian supply. In one of the finest interior cities using about twenty million gallons, it was found that, everythin" figured in, filtered water delivered to the user actually costs four to five times as much as would an Air Lift supply. Artesian or Well Supply. Many of our interior sections must depend upon well water, and there are few districts where an ample supply is not to be secured fiom wells properly made. This water is generally pure and whole- some. It is also of uniform temperature the year round—cool and pleasant in the summer, because the underground pipe and soil tem- pel ature remain uniformly low. In winter, well water, being warmer than that taken from lakes and rivers, is not so apt to freeze, and, from all considerations of temperature and purity, well water is greatly to be preferred. Many cities located on rivers having a gravel bed formation find that, by placing wells of suitable construction far enough back from the bank, there is a natural filter bed, leaving the water perfectly clear, even when the river itself is chronically muddy. When river or other surface water is good the wells may be drilled close to the edge, the water flowing down from the top of the wells. . Even when the supply near the surface is either scanty or unsafe, it is usually possible to sink driven wells to greater depths, thus “cas- ing off” all suspected water and drawing only from deeper rock or gravel veins removed from all danger of surface contamination. The natural head from lower veins often maintains the water near the surface so that power only need be expended for moderate lifts. There are not many underground formations where wells should be located close together. Such wells may affect or rob each other and it is usually best to spread them out on a line across what is known to be the underground flow. Some finely creviced or tight rock formations have a strong head with but little capacity and wells m such formations, if pumped hard, yield but little additional water 9