Artesian Water for Minneapolis. — Winchell. 275 
ascertained but of course it is the St. Peter sandstone, and the 
water contained in the St. Peter sandstone, more or less under 
hydrostatic pressure at that place, permeates the drift sand and 
rises through these tubes and overflows at a hight of about, as 
I said, twenty feet above Bassett's creek. It is conducted in un- 
derground pipes and rises to the roof of the buildings adjacent 
where it is allowed to flow constantly and from which buildings 
it is conducted into wagon tanks by the simple action of gravity. 
The capacity, or rather the amount of water supplied, by these 
"springs" for the city of Minneapolis daily is about 10,000 
gallons, and the superintendent stated that they could supply 
ten times as much if there were a demand. It might also be 
added that if there were a demand these same little artesian 
wells could be sunk — say 100 feet deeper, and would furnish 
perhaps several million gallons daily, and if the number of 
these wells were increased the reservoir would probably be 
found inexhaustible, in the same manner as other wells sunk 
in the St. Peter sandstone. 
From what has been stated it will be seen that the water de- 
rived from the St. Peter basin cannot mingle with the surface 
drainage water throughout the area of this belt or gorge for- 
merly occupied by the Mississippi river, that is, not on a 
large scale. The surface waters are shed either by the Trenton 
limestone or by the laminated clay or by the till and produce a 
series of springs which is entirely distinct from any spring 
which issues from the St. Peter sandstone, although, of course, 
there may be subterranean seepages and sometimes considerable 
passages which will conduct the surface water into the under- 
ground reservoir even in the limits of Minneapolis. These 
small seepages downward of the surface water, however, are 
very inconsequential, since the underlying water is under hy- 
drostatic pressure and the tendency is for the underlying water 
to crowd upward to the surface, driving the surface waters 
away. Thus, the subterranean rock basin is kept pure in the 
city of Minneapolis, not admitting the surface water, while at 
more remote points, where the St. Peter sandstone rises to the 
natural surface, it necessarily receives the surface water freely, 
a fact which has already been mentioned and which constitutes 
the supply which maintains the underground waters of the 
basin. 
