Underground Rivers - University of New Mexico

He dismissed the role of rainfall in springflow.
Chapter 3 -- Roman Encyclopedists
Some suppose that all the water that the earth drinks in from rain is sent out again into the
rivers... [But] a great deal can obviously be urged in reply to this. First of all, as a diligent
digger among my vines, I can affirm from observation that no rain is ever so heavy as to wet the
ground to a depth of more than 10 feet... How, then, can rain, which merely damps the surface,
store up a supply sufficient for rivers?
Rain only feeds the regular rivers and creates temporary torrents. As water is “a quarter of
nature,” there can be no shortage of it. “Rains cannot produce; they can only enlarge and
quicken a river.”
Seneca side-steps the mystery of the Nile's origin by citing 500-year old Greek thought.
Oenopides of Chios... says that in winter heat is stored up under the ground; that is why caves
are then warm, and the water in wells is less cold. The veins of water are dried up by this
internal heat, he thinks. In other countries rivers swell through rain but the Nile, being aided by
no rainfall, dwindles during the rainy season of winter.
As for springs, we should offer sacrifices.
Soil moisture, seen by Seneca in global perspective, moves from north to south.
The next account is that of Diogenes of Apollonia... The whole earth is full of perforations, and
there are paths of intercommunication from part to part. From time to time the dry parts draw
upon the moist. Had not the earth some source of supply, it would ere this have been
completely drained of its moisture. Well, then, the sun attracts the waves. The localities most
affected are the southern. When the earth is parched, it draws to it more moisture, just as in a
lamp the oil flows to the point where it is consumed, so the water inclines toward the place to
which the overpowering heat of the burning earth draws it. But where, it may be asked, is it
drawn from? Of course, it must be from those northern regions of eternal winter, where there is
a superabundance of it.
Now, one would like to ask Diogenes, seeing the deep and all streams ire in
intercommunication, why the rivers are not everywhere larger in summer? ...Another questionseeing
that every land attracts moisture from other regions, and a greater supply in proportion
to its heat, why is any part of the world without moisture?
Regarding underground rivers,
Rivers are no less existent under the earth merely because they are not seen. You must
understand that down there rivers as large as our own glide along, some flowing gently, others
resounding in their tumbling over the broken ground. What then? Will you not equally allow
that there are some lakes underground and some waters stagnating there without exit?
Throughout the entire earth, one of them says, run many different kinds of water. In some
places there are perpetual rivers large enough to be navigable, even without the help of rains.
Moving air in the lower region inside the earth bursts the atmosphere, thick and complete with
clouds, with the same force that clouds in our part of the world are usually broken open.
Now permit me to tell you a story. Asclepiodotus is my authority that many men were sent
down by Philip [Philip II of Macedon (382-336 BC), father of Alexander the Great] into an old
mine, long since abandoned, to find out what riches it might have, what its condition was,
whether ancient avarice had left anything for future generations. They descended with a large
supply of torches, enough to last many days. After a while, when they were exhausted by the
long journey, they saw a sight that made them shudder: huge rivers and vast reservoirs of
motionless water, equal to ours above ground and yet not pressed down by the earth stretching
above, but with a vast free space overhead.
Heron of Alexandria (10-70) was a Greek engineer and geometer in Roman times. Hero is
credited with the first documented steam engine, the "aeolipile." In Dioptra he notes,
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