teaching - Earth Science Teachers' Association

TEACHING EARTH SCIENCES ● Volume 30 ● Number 1, 2005
for the Grand Duke concentrating on muscles but also
added his own observations on fossils and sediments.
This led to an interesting year for Steno who had decided
to see for himself the relationship between seashells and
rocks. He spent two years travelling around Tuscany with
the Grand Duke’s blessing, looking at strata and fossils and
even travelled to Elba to see the famous pyrite mines. He
concluded that ‘the fossils shells found in rocks in many
places are the remains of animals that once lived there’.
However two monumental events happened to him. He
became Catholic and he was summoned back to Denmark
by his King Frederick III.
He realised that the research opportunities he had access
to were about to end and so he returned to Florence and in
1667-9, he wrote his famous geological text De solid Intra
Solidum Nauraliter Contento Dissertationis Prodramus
(Forerunner of a dissertation of a solid naturally contained
within a solid). This basically asked the geological question
‘how can a solid like a shell or crystal become enclosed by
another solid’ In his publication Steno recognised:
● The enclosed body had to be solid before the enclosing
rock solidified.
● Rock strata below in a cliff had to be complete by the
time the layer above was deposited.
● Metalliferous veins were younger that the rock which
encloses them.
● Crystals can grow in fluid filled cavities and thus crystal
faces retain their angularity despite their distorted symmetry.
All of these were based on observations that were his own,
and caused conflict with accepted religious beliefs at the time.
After problems with one of the censors before publication,
Steno spent more time upon religious matters and
after Ferdinando’s death in 1670 he came under the influence
of Cosimo III who had little of his father’s intellectual
flare. After 2 years he was summoned back to
Copenhagen again by his king, this time with the promise
of religious freedom. He was still a Danish subject. In 1673
Steno gave his last public appearance as a scientist in
Copenhagen and he decided to abandon his life in science
and concentrate on religion.
He returned to Florence and in 1675 became a priest and
then in 1677 he walked from Florence to Rome to become
a bishop. Steno was then sent to Germany to convert the
Lutherans to Catholicism. His area was northern and western
Germany, Denmark and Norway. He had a difficult job
and fasted and lived simply without home, clothes or
money. He dedicated himself to his religion. He died on
November 21, 1686 from starvation, poverty and self
inflicted austerity. He had no worldly possessions except
some books and religious goods. When Cosimo heard of
his death he sent money to have his body returned to Florence
for a decent burial. However because of nautical
superstitions about transporting dead bodies he returned as
a box of books – a suitable ending for an academic!
Steno’s contribution to geology from De Solido was
fundamental to the growth of our science. Today every student
of geology learns Steno’s 3 basic Principles:
● Principle of Superposition, which forms the basis of
stratigraphy and allows us to ask – What came first
rather than – How old is it We had to wait a further two
and a half centuries before we could answer this.
● Principle of Original Horizontality i.e. If the present
strata has an angle of dip, if that sediment was deposited
from water it would have originally been horizontal.
● Principle of Lateral continuity i.e. water lays down sediments
as laterally continuous sheets ending only at the
edge of the basin.
These three principles were the contribution of a bishop
who like many famous geologists died in poverty. However
Steno must surely be unique having been beatified by
Pope John Paul II in 1988.
Nicholaus Steno led a life of conflicts and contradictions
but he had the courage to give us the Principles to carry on.
Refs:
Cutler A, 2003,
The Seashell on the Mountaintop,
Heinemann, London. ISBN0434008575
Faul H & Faul C, 1983,
It began with a stone, Wiley Interscience.
ISBN 0471896055
Dr Cynthia Burek
University College Chester
c.burek@chester.ac.uk
33 www.esta-uk.org