Underground Rivers - University of New Mexico

Chapter 3 -- Roman Encyclopedists
Instances of rivers that flow underground -- and come to the surface again are the Lycus in
Asia, the Erasinus in the Argolid and the Tigris in Mesopotamia; and objects thrown into the
Baths of Aesculapius at Athens are given back again in Phaleron Harbor [about 10 kilometers
distant]. Also a river that goes underground in the Plain of Atinas [in modern Turkey] comes
out 30 kilometers further on, as also does the Timavus in the district of Aquilea.
We will see more to the Timavus connection in Chapter 72, Underground and Balkanized.
Pliny observed an underground river from Lake Vadimo in Etruria (modern Tuscany), the scene a
310 BC battle.
The water is sky-blue; its smell is sulfurous, and its flavor has medicinal properties, and is
deemed of great efficacy in all fractures of the limbs. This lake empties itself into a river, which,
after running a little way, sinks underground, and, if anything is thrown in, it brings it up again
where the stream emerges.
The Nile originates "in a mountain of
lower Mauretania," flows above
ground for "many days," again flows
underground, reappearing as a large
lake in the territories of the
Masaesyli, then sinks once more
below the desert to flow underground
"for a distance of 20 days' journey till
it reaches the nearest Ethiopians."
We'll return to this subterranean route in Chapter 71, Sub-Saharan Streamflow and Shambhala,
but let us here note that the source of the Nile would baffle geographers for another two millennia,
as evidenced by The Earth: A Descriptive History of the Phenomena of the Life of the Globe
(1871) by Elisee Reclus.
The Nile does not receive a single visible affluent; nevertheless, it must necessarily be
replenished by several underground tributaries, for its liquid mass is much more considerable in
Egypt than in Nubia.*
Pliny the Younger (61-114) reported that his uncle, commanding the fleet at Misenum, ordered
his ships to cross the Bay of Naples for a first-hand look at Mt. Vesuvius where the fumes and
ash became so strong that they suffocated him.
Considering the consequence of Pliny the Elder's field trip, perhaps we should be less harsh on
the encyclopedists who worked from their offices in Rome.
A spring near Como said to ebb and flow three times a day was mentioned by the younger Pliny
in a letter written between 98 and 108 AD. He suggested several explanations:
a) Glugging, as in a bottle being emptied.
b) The influence that causes tides in the sea.
c) In the way that a river may be hindered by wind and tide.
d) A subterraneous "poise" [balance or equilibrium], valve-like, that when the reservoir is dry
allows the spring to operate, but when full, chokes it.
e) Or is there rather a certain reservoir that contains these waters in the bowels of the earth,
which while it is recruiting its discharges, the stream flows more slowly and in less quantity,
but when it has collected its due measure, it rises again in its usual strength and fullness.
This last explanation might be a siphon, the subject of Chapter 44, but Pliny did not understand
the mechanism.
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