Jost Burgi
Jost Bürgi (also Joost, Jobst; Latinized surname Burgius or Byrgius), 28 February 1552 – 31 January 1632, was active primarily at the courts in Kassel and Prague, was a Swiss clockmaker, a maker of astronomical instruments and a mathematician. See Wikipedia entry.
A sextant made by Bürgi is on display in Prague National Technical Museum.