Ludolph's number or Ludolphine number: pi

For some time the transcendental number pi (π) was known in Germany as Ludolph's number or Ludolphine number. This name derived from the name of a German mathematician from Hildesheim, who emigrated to the Netherlands, where he taught fencing and mathematics in Delft and Leiden: Ludolph von Ceulen (1540-1610), also known by his latinized name Colonus. Ludolph van Ceulen (note the change from the German von to the Dutch van, meaning of or from in English) evaluated π to over 30 digits—long before the age of digital computing— by using the polygon method of Archimedes.

Keywords: mathematics, geometry, history, circle, radius, circumference, approximation of trancendental number

References:
R. M. Th. E. Oomes, J. J. T. M. Tersteeg and J. Top: Het grafschrift van Ludolph van Ceulen. Nieuw Arch. Wiskd. Juni 2000, 5/1 (nr. 2), pp. 57-62.
Internet: Ludolph's number and Ludolph van Ceulen.