At Mammoth Spring, Ark., and under the shadow of the Ozark Mountains,
is the largest spring in the world. The water comes up in such a body
that it forms a lake about the orifice. The output of the spring is
29,600,000 gallons daily. Records have been kept of it for ten years,
and during that time the output has not varied 100 gallons a day nor
the temperature a single degree. Winter and summer the spring remains
at 59 degrees. The spring is evidently the outlet of some underground
river.
* * * * *
The Poncho springs in Colorado are all on the side of a mountain, and
hot and cold water flows from the ground in places not more than three
inches apart.