π Tombstone of Ludolph van Ceulen
Approximations on the memorial of a π calculator
The restored tombstone of π calculator Ludolph van Ceulen features engravings of digits of π placed in a circle with bounds to π (3.14159265358979323846264338327950288 < π < 3.14159265358979323846264338327950289) appearing in the middle.
Ludolph van Ceulen spent a major part of his life calculating the numerical value of the mathematical constant π. After his death in 1610, digits of π were engraved on his tombstone in Leiden, together with upper and lower limits given as fractions. The tombstone was eventually lost, but later restored in 2000. The text on the tombstone reads, "Buried here lies Ludolph van Ceulen, Dutch professor of mathematical sciences in the vocational school [Engineering School in the Faliedenbegijnkerk] of this city. [He was] born in Hildesheim in the year 1540 on the 28th of January [and] died the 31st of December 1610. In his life, with great effort, he found the ratio between the circumference and diameter of a circle as here follows."