Ole Christensen Rømer, 25 September 1644, Århus – 19 September 1710, Copenhagen) was a Danish astronomer who in 1676 made the first quantitative measurements of the speed of light.
Observatorium Tusculanum was an observatory Ole Rømer build in 1704 which he used until his death 1710.
After Rømers death in 1710 continued his pupil, Lauritz Th. Schiwe as professor of astronomy observations from the observatory, but he died already in the years after the plague years in 1711. Without maintenance, the Center due thereafter, and approx. 1716-17 instruments were moved to the observatory of the Round Tower, where they also went up in flames by fire in 1728 along with all the familiar notes from Observatory Tusculanum (at least three foliobind) except Triduum observation ( "The three days of observations from 20 . October kl. 16 -23. October kl. 18 in 1706).