Geoscience Reference
In-Depth Information
until after his death, and are contained in the Discourse of
Earthquakes which was edited by his friend Richard Waller in 1705.
Other ideas, such as some on minerals, appeared in his Micrographia.
Unlike Steno, Robert Hooke was not too concerned with framing his
geological ideas within a religious context. While Steno was aware
that minerals had particular shapes, Hooke's ideas, published four
years earlier, were more complex and comprehensive. He realised
that their external or crystallographic shape was controlled by an
internal arrangement of matter, a concept he tried to promote and
explain through the use of illustrations in which spheres (or 'globules'
or 'bullets' as he called them), were packed in different arrangements
to make up different outline shapes. Today we know that minerals
have a defined and regular chemistry and atomic structure, which
controls the external habit of the mineral species.
Having been brought up on the Isle of Wight, Hooke would have
been familiar with the different arrays of fossils found in the various
horizons that form fabulous coastal exposures at so many points
around the island. He probably made collections of such specimens,
and he was certainly conscious that they represented the remains of
actual organisms. He had no time for the folklore that was attached to
these past animals, and a fine suite of ammonites illustrates his work.
These spectacular fossils were cephalopod molluscs, which were abun-
dant in the Mesozoic oceans and were similar in morphology and life
habit to the modern-day Nautilus that is found in the Indian Ocean.
He also recognised that animals living today might not have been alive
in the past, and conversely that some animals were present in the past
but no longer present today: 'there have been many other species of
Creature in former Ages, of which we can find none at present; and
that 'tis not unlikely also but there may be divers [diverse] new kinds
now, which have not been from the beginning.' He noted that past
events could be recognised and dated by changes in the fossil record.
This forecast the science of biostratigraphy, the dating of the geolog-
ical record using fossils. He was also anticipating some of Charles
Darwin's notions of over a hundred years later.
