AND THEIR RELATION TO IRRIGATION. 15 
as yet developed are those of Denver and the San Luis 
Valle} 7 , the latter of which is the most important, and 
one of the most important in the country, whether judged 
by its extent, the ease and cheapness of sinking; or the 
amount of water found, . , 
THE DENVER BASIN. 
It was in this basin that the first development to any 
extent of artesian water in the State was made. Reports 
upon this basin have been made by the Colorado Scien-. 
title Society in 1884, and in the U. S. Artesian Wells 
Investigation previously referred to. As the writer has 
there described the wells in detail, it will be here referred 
to only to illustrate some of the characteristics of basins 
which are plainly shown by experience therein. 
The basin is shown by the map, which is reduced 
from one given by the writer in the Government report. 
The location of the wells is shown by. the small circles. 
t/ 
Where the water did not reach the surface the circle is 
underlined, and the figures attached indicate the distance 
the water came from the surface. The limits of the flow¬ 
ing wells are indicated by the dotted line, on each side of 
the Platte. 
The basin is instructive, because it shows the effect 
of putting down many wells in a small area. 
The early wells were nearly all put down for domes¬ 
tic purposes, and were small in size. The water was ex¬ 
cellent for boilers, and the increased demand led to the 
putting down of larger wells and to the use of pumps for 
factories, hotels and other large users. The result has 
been that nearly all have ceased to flow. In the Charles 
well, which was the first to reach the 600-foot stratum, 
the pressure was quite constant, and about 70 pounds per 
square inch. When the Daniels A Fisher well was sunk 
to the same depth not far away, the pressure was imme- 
