Birth date: 
Birth place: 
Date of death: 
Place of death: 
12 June 1577 
St Gall (now Sankt Gallen), Switzerland 
3 Nov 1643 
Graz, Austria 
Paul Guldin was named Habakkuk Guldin at his birth. He became a goldsmith and worked at that during his teens. Although of Jewish descent his parents were Protestants but Guldin became a convert to Catholicism at the age of 20 and joined the Jesuit Order. At this point he changed his name to Paul. In 1609 he was sent to the Jesuit Collegio Romano in Rome where he studied under Clavius . After this he taught at Jesuit Colleges in Rome and Graz. He was also professor of mathematics at Vienna from 1623 until 1637 when he returned to Graz. In the middle of his years in Vienna he spent some time at the Silesian principality of Sagan. Guldin corresponded with Kepler , but on religious topics not mathematics or astronomy. Guldin's most important work is in 4 volumes. In Volume 1 centres of gravity are considered, in particular he discusses the centre of gravity of the Earth. Volume 2 contains Guldin's Theorem: If a plane figure is rotated about an axis in its plane then the volume of the solid body formed is equal to the product of the area with the distance travelled by the centre of gravity.
Volume 3 contains work on cones, cylinders and solids of revolution.
Source:School of Mathematics and Statistics University of St Andrews, Scotland
