Nicolaus Samuelis Cruquius

Niklaas Samuel Cruquius (Latinized: Nicolaus Samuelis Cruquius or Kruikius , actually Nicolaas Kruik ; * December 2, 1678 in Vlieland , Friesland; † February 5, 1754 in Spaarndam , North Holland) was a Dutch hydraulic engineer , surveyor and cartographer . Like many of his contemporaries, he gave himself a Latin name.

Cruquius is famous for his temperature measurements, which are still used today in historical weather research. The Netherlands was one of the first countries in which weather records were made and so measurements from over 300 years are available.

The meteorologist Cruquius

On December 19, 1705, Cruquius began to measure temperature, air pressure and precipitation three times a day. To do this, he used simple instruments, such as a bowl for measuring precipitation and an air thermometer. He also devised his own graduation, as there was no universal thermometer scale yet. From 1727, the Amsterdam-based instrument maker Daniel Gabriel Fahrenheit experimented with mercury thermometers and introduced the Fahrenheit scale. Cruquius then converted his old measurements into degrees Fahrenheit. The records still exist today.

In 1717 Cruquius went to Leiden to study medicine with Herman Boerhaave . Through him he became a member of the British Royal Society .

He had close contacts with an English meteorological organization, which prescribed how measurements had to be carried out. Therefore we know how Cruquius measured, and so the Royal Dutch Meteorological Institute (KNMI) was able to reconstruct its measurements from 1706 to 1734. From 1734, records were also made in other parts of the Netherlands.

Cruquius noted the air pressure, precipitation and humidity. Little is known about its barometer. He measured the humidity using an in Salmiak soaked sponge and a scale. He derived the wind speed from the revolutions of a windmill .

Cruquius was so convinced of the usefulness of his weather observations for the protection of the Netherlands against the increasing violence of storm, sea and rain that he called in 1725 at the then government, the Staten van Holland, and asked for financial support for his weather observations. He foresaw the problems of rising sea levels and the silting up of the IJ . He also worked out plans to pold the Haarlemmermeer , as it was getting bigger and threatened the cities of Haarlem and Leiden more and more. With these considerations he was way ahead of his time.

His request for a central institute for meteorology was rejected, partly because it was not taken seriously, partly for political reasons because the individual provinces wanted to retain their autonomy. The Rijkswaterstaat , founded in 1798 , (construction and maintenance of waterways and roads) can be seen as the result of his considerations. Around a hundred years later, Christoph Buys Ballot came up with a similar request, and then the KNMI was founded. Whether Ballot relied on Cruquius' ideas is unknown.

Cruquius, disappointed about the rejection of his request, withdrew and in the last years of his life was chairman of the Hoogheemradschap Rijnland , which was involved in the construction and maintenance of dikes in the area from Wassenaar to Amsterdam and IJmuiden to Gouda .

By the time Cruquius died in 1754, the perfectionist had detailed his funeral, inheritance, and even the inscription on his tombstone. In his honor, a pumping station on the ring canal around the Harlemmermeerpolder was given the name De Cruquius pumping station and the town where it was built.

source

• KNMI website

Web links

• Historical weerkundige waarnemingen, AFV van Engelen en HAM Geurts, Nicolaus Cruquius (1678–1754) and his meteorological observations, De Bilt, 1985 (PDF file; 4.95 MB)
• Entry for Cruquius, Nicolaus (1678-1754) in the Archives of the Royal Society , London