In 1777, the Danish astronomer Thomas Bugge (1740-1815) was appointed professor of mathematics and astronomy at the University of Copenhagen. Keen to modernize the existing observatory on top of the Round Tower, he travelled through Germany to Holland and England to learn more about the state of astronomy and instrument-making in these countries. During his tour he kept a journal in which he noted what he saw, whom he met and which books and instruments he bought. He also included dozens of sketches and drawings, which greatly add to the historical value of his manuscript. The document lay undi.