Tycho Brahe days list. One should also note that Denmark was on the Julian calendar until 1700, when it switched to the Gregorian calendar. Medieval calendars often contained lists of "dies Ægyptiaci", "Egyptian days", that also were held to be unlucky. The Egyptian days were: These too were days considered unlucky to begin any enterprise. Physicians were especially discouraged from performing bloodletting on the Egyptian days. Tycho Brahe days In the folklore of Scandinavia, Tycho Brahe days (Danish: "Tycho Brahes-dage"; Norwegian: "Tycho Brahedager"; Swedish: "Tycho Brahe-dagar") are days judged to be especially unlucky, especially for magical work, and important business transactions[ and personal
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