Definition and History of Hydrogeology - Hydrogeology: Objectives, Methods, Applications - page 6

And yet, his ideas did not take hold, and the generally accepted theory
was that of the underground still (Figure 1), where water passed below
ground through channels, was heated by a central fi re and abandoned
its salt, and then condensed in the mountains to feed underground lakes,
which fl owed out at the surface as springs.
Figure 1 The underground still: 17th century engraving.
1.2.4 The 17th century: the water cycle
Modern geology is being born in the West. A few major works dealing
with subterranean water can be found: “ Mundus subterraneus” (Athanasius
Kircher, 1665), “ Principia Philosophiae” (Descartes, 1664), “ Prodromus”
(Stenon, 1669); but they restate the concept of the underground still. It
is in 1674 that Pierre Perrault's “On the Origin of Springs” reveals the
importance of evaporation and infiltration. Perrault proved that the
upper Seine's discharge corresponded to only a sixth of the amount of
water entering the river's watershed. A large percentage of the water had
therefore disappeared. Mariotte (1620-1684) came to the same conclusion,
and during the same period, Halley (1656-1742) quantifi ed evaporation.
The motor bringing water from ocean to mountains and the mechanism
for desalinization were thus discovered at the same time. The modern
conception of the water cycle was, then, born in the 17th century, after
more than two thousand years of debate amongst the greatest scientists
on the planet.