Geoscience Reference
In-Depth Information
wood, Dutch avidity, and soon rotted. In 1646 the top was replaced by expensive
and heavy marble. The architect's warning in 1620 not to add heavy load for the
tower's stability was forgotten. In 1650, a windstorm made the tower lean (3.5 feet
off plumb). It was decided to put the tower straight and Claes Jeremiasz Persoons,
a master stonemason, succeeded in doing so, earning eternal fame. With the newest
pile driving machines, by hand, 500 wooden piles of 12m length were driven just
outside the existing foundation into a sand layer at 17 metre deep, next by horse
power and heavy iron chains the tower was put straight - so it is written - and
finally new brick-work buttresses, still visible to day, (Fig 1.7) carry the tower.
How Persoons moved and twisted this heavy tower remains a miracle.
Figure 1.7 Putting a heavy church tower straight in 1655
The trade by sea with the orient was flourishing. Cities required good connection
with the sea, asking for high river levels. On the contrary, farmers and landowners
demanded protection against high waters. To support solving this level contest, the
Dutch ruler, Prince Maurits, founded the institutionalisation (diploma) of
geometricians and fortress builders (military engineers). In 1583, Simon Stevin, a
famous Flemish mathematician and excellent military engineer, started for this
purpose the Duytsche Mathematique at the university of Leiden. By this innovation
the water regulation by precise levelling became possible. Geometrician Cruquius
was one of the pioneers in making detailed river maps and the spirit level
instrument developed by Huygens was of great importance. Hydraulic problems
Search WWH ::
Custom Search