Kaiser, Frederik [Frederick, Friedrich]

Born Amsterdam, the Netherlands, 10 June 1808

Died Leiden, the Netherlands, 28 July 1872

Frederik Kaiser directed the Leiden Observatory from 1837 until his death in 1872. His contributions to Dutch astronomy included the foundation of a completely new observatory building in Leiden (in 1860, the first of its kind in the Netherlands) and the introduction of statistics and precision measurements in daily astronomical practice. Moreover, he was a gifted teacher and a skillful popularizer of astronomy.

Kaiser was the oldest boy of eight children born to Johann Wilhelm Keyser and Anna Sibella Liernur. His parents were immigrants from Nassau‐Dietz in Germany. Kaiser's father, a teacher of German, died in 1817 when Frederik was 8 years old. Kaiser was then raised by his uncle, Johan Frederik Keyser, a municipal employee and teacher of mathematics in Amsterdam. Keyser was a member of several learned societies and was known as a proficient amateur