Geology
Early observations
on rocks were greatly conditioned by man's rather few means of
access to the interior of the earth. In Italy notes had been made
on volcanoes from Leonardo onwards ; in Germany, notes on mines
from Agricola onwards ; in most countries, notes on fossils. In
France about 1750, extinct volcanoes began the train of
decisive discoveries. In Germany, not much later, mining provoked
the serious classification of rocks. In Great Britain the surface
cuttings and canals of the agricultural and industrial revolutions
aroused the curiosity of Hutton and W. Smith. In the early work,
partly palaeontological as it was, botanists bore a large
share.
Leonardo da Vinci,
Giordano Bruno, Stevinus, and other men of the Renaissance, with
their vivid freedom from tradition, at once reached such
common-sense conclusions as, that the rivers had sculptured the
valleys, that some rocks had once been molten, that the sea, which
is (Bruno) always near active volcanoes, must have some connection
with them, that the land and the sea may not always have been in
their present positions. But the clarity of these early views was
soon lost. It was unsupported by work in the field, and put side by
side with pre- scientific ideas. Fossils, for example, were Sports
of Nature played on mankind, or the earth's imperfect successes in
its efforts at the (spontaneous) generation of life.
Agricola
(1494—1558) was a recognised mining expert. He made
observations on crystals, their cleavage, lustre, colour, hardness,
and was among those whose imagination was struck by those columnar
formations of basalt (such as the Giant's Causeway in Ireland)
which were to prove crucial later on.
Regularly stratified
rocks and their faults have always been a central theme for
geological curiosity. Steno (1638-86), a Dane, was an early worker
on this (Italy, 1669). Men began to dream of geological maps,
though ordinary ones were still of the crudest.
