Tycho Brahe days days in the year pregnant with misfortune, wherefore in Denmark, up to this very day, the laboring class call such days on which they happen to meet with some unfortunate accident, Tycho Brahe's days." In his travelogue "A Poet's Bazaar", Hans Christian Andersen alludes to the fact that Tycho Brahe died in exile in Prague, observing that "Denmark owns not even his dust; but the Danes mention his name in their bad times, as if a denunciation proceeded out of it: 'These are Tycho Brahe's days!' say they." However, no mention of the Tycho Brahe days is actually found in
Armillary sphere the crown escapement which has been developed from 14th century, and is applied to gear system which had been improved until the middle of 17th century in Western-style clockwork. In particular, timing device of Song I-yŏng's Armillary Clock adopts the early 17th century pendulum clock system which could remarkably improve the accuracy of a clock. Further advances in the instrument were made by Danish astronomer Tycho Brahe (1546–1601), whose elaborate armillary spheres passing into astrolabes are figured in his "Astronomiae Instauratae Mechanica". Armillary spheres were among the first complex mechanical devices. Their development led to many improvements in techniques and