Geoscience Reference
In-Depth Information
14
AFTERWORD - A SHORT HISTORICAL
SKETCH OF THEORIES ABOUT THE
WATER CIRCULATION ON EARTH
14.1
EARLIEST CONCEPTS: THE ATMOSPHERIC WATER CYCLE
For as long as humans have been on Earth, they must have been acutely aware of their
dependency on different forms of water in their environment. Water was literally vital
for their health and sustenance but it could also be destructive and even lethal in severe
weather, floods, and the other hazards they faced in their daily lives. Already in the earliest
writings there are indications that among natural peoples in their primal stage it was a
common notion that water in nature moves continually between different states in some
repetitive, if not cyclical, fashion. Whatever is left of these early writings is not always
easy to interpret, mainly because the meanings of even the most elementary concepts
have evolved in the meantime. Nor is it always easy to distinguish profane views and
naturalistic descriptions from the more sacred narratives and religious interpretations.
Nevertheless, a cursory scan of some better known early writings yields several instances
of water related imagery even in widely different cultural settings, in which the evidence
is fairly clear, and which provide some idea on the thinking of early humans.
As early as the eighth century BCE in Greece, the poet Hesiod presented a remarkable
description. In a passage with advice to farmers to get dressed warmly and to finish the
work in time (Hesiode, 1928; also Hesiod, 1978; vv. 547-553), he wrote the following.
For the morning is cold when Boreas [the north wind] bears down; in the morning from the starry
sky over the earth a fertilizing mist spreads over the cultivations of the fortunate; this [mist], drawn
from ever flowing rivers, and lifted high above the earth by a storm wind, sometimes falls as rain
toward evening, or sometimes blows as wind, while Thracian Boreas chases the heavy clouds.
This passage contains interesting features; it explains that mist is derived from river
water, and that it may lead to rain; on the other hand, it implies that evaporation may be
both a result and a cause of the wind. Apart from the reference to Boreas, the god of the
north wind, Hesiod's passage appears quite naturalistic.
Several water cycle related passages appear in the Hebrew Bible. The oldest among
them, written in the eighth century BCE, is probably (5,8) in the Topic of Amos; it reads
as follows (see, for example,
Oxford Study Edition
, 1976).
He . . . who turned darkness into morning and darkened day into night; who summoned the waters
of the sea, and poured them over the earth;...hewhodoes this, his name is the Lord.
Amos, a native of Judah, was by his own account originally a shepherd and a pruner of
sycamore fig trees. From the context, that is from the first part of this quotation which
refers to the cycle of day and night, it is possible that the second part refers to some kind
