The arrangement was that he should take over the teaching duties since his father was too ill to continue but, should his father recover, he had to stand down. Since Rudolph died a month later, Snell was required to continue teaching but he struggled to get proper recognition from the University of Leiden.
He was made a full professor of mathematics in February but his salary was not increased. Slowly he received increases but only in did he receive what he considered the proper amount for his position. In , at the age of 46 , Snell died from colic which caused a fever and paralysis of his arms and legs. His illness lasted two weeks [ 3 ] :- When Snell had fallen ill, the medical doctors In the evening of 30 October, [ the doctors ] went to visit Snell to see the effects of a new medicine.
This had not helped at all and after giving him a suppository for some relief, they left. Snell had dinner with his wife. Because he was not able to walk, his servants had to lift him up. He then suddenly lost consciousness and died, 46 years old. He was buried on 4 November in the Pieterskerk in Leiden. Twenty students carried his coffin. Let us now look briefly at the contributions he made after being appointed as a professor at Leiden. He proposed the method of triangulation and this work is the foundation of geodesy.
Bowie writes [ 6 ] :- Willebrord Snell He was really the originator of triangulation, which is now the universally employed method in surveying and mapping large areas. He published a book in Leiden describing his work in In observing the angles of the triangles of his arc he used a quadrant of a circle of about two feet in radius.
This was graduated to two minutes and readings were estimated to single minutes. In this work Snell attempted to measure the circumference of the earth and so required a considerable number of measurements. To make these he had to travel quite widely in the Netherlands but leaving his family in Leiden caused him unhappiness. He used as a baseline the distance from his house to the local church spire, then built a system of triangles which allowed him to determine the distance between the towns of Alkmaar and Bergen-op-Zoom which is around km.
His measurements were surprising accurate allowing him to deduce a good value for the radius of the earth. Throughout his career Snell was interested in astronomy and published several works on that topic some, but not all, of which contained data from his own observations. In this latter work Snell strongly criticised Aristotle and stressed how harmful to the development of science it was to continue to treat his views with such reverence.
Of course, in so doing Snell was following the teaching of Ramus and of his own father. Despite his attack on Aristotle , Snell did not accept Copernicus 's heliocentric system but firmly believed in an Earth centred system. Although he discovered the law of refraction now known as "Snell's law" in , a basis of modern geometric optics, he did not publish it and only in did it become known when Christiaan Huygens published Snell's result in Dioptrica.
There is a manuscript by Snell's which is an outline of a treatise he intended to write on optics. It is now in the library of the University of Amsterdam and known as the 'Amsterdam manuscript'. Klaus Hentschel in [ 10 ] tries to construct the path which led Snell to discover Snell's law:- Because of his geodetic work in which he pioneered the method of triangulation, Snell already had considerable experience with trigonometric functions; indicative of this are the two allusions to geodesics in the Amsterdam manuscript, one of them directly before the law of refraction Other remarks in the manuscript reveal that Snell had studied the existing literature on optics, particularly on refraction; various passages in the manuscript are analogous in formulation and sequence to other treatises as shown by his marginal notes and occasional references to other texts interspersed throughout the manuscript.
Categories : Dutch mathematicians Dutch scientists births deaths. Willebrord Snell From Academic Kids. Toolbox Special pages. This page has been accessed times. About Academic Kids Disclaimers. During his travels, he met with other academic professionals and studied various subjects along the way. One of the people he spent a lot of time with on his travels was Tycho Brahe.
Because of this, Willebrord Snell began working at the University of Leiden, where his father spent much of his time. He would often give lectures for his father. This did not automatically give Willebrord Snell a full teaching position at the University, but it did allow him to take on some more work than he had when he was just working with his father.
However, his workload was still light enough that he could focus on his own studies these studies were self-guided; he did not take any further classes.
His main topics of study were mathematics specifically geometry and astronomy. He loved to study how these subjects worked together. He wrote several papers and books on these topics. He even wrote commentaries and other works on the work of other mathematicians and astronomers.
It was around that Willebrord Snell made one of his most impressive discoveries. Using methods used by the ancient Egyptian Eratosthenes, and some methods of his own, Willebrord Snell was able to use various high points and the distances between them to calculate the circumference of the Earth.
It was also in that Willebrord Snell finally became a full professor. Up until this point, he acted more as a modern-day lecturer or assistant professor.
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