Paul Guldin

Guldin, originally Habakkuk Guldin (* June 12, 1577 in Mels, † November 3, 1643 in Graz ) was an astronomer and professor of mathematics in Graz and Vienna.

Guldin first learned the goldsmith's art. He was baptized a Protestant, came in 1597 to Catholicism and took it to the name Paul. Shortly after, he entered the Jesuit Order in Munich. There they recognized his talent for mathematics, and sent him to Rome for further training. Then he taught in Rome, Vienna and Graz.

His greatest work Centrobaryea appeared in four books in 1635, 1640 and 1641 in Vienna, and also contains the Zentrobarische rule or barycentric rules, now called Guldinsche rules with which you can calculate volume and surface of solids of revolution. These rules, however, were already described in about 300 AD by Pappus of Alexandria in his math textbook, so that it is actually this is a rediscovery.

Guldins about 300 -volume private library is now owned by the University Library of Graz.