Fancy wearing a portable sundial around your neck and use it when they ask you in the bus stop what the time was? Have you ever thought what time pr the sun and the cycles of the day mean for us humans and for our planet? Without time and equipments measuring time we would be completely lost. Portable sundials were wildly used from the middle of the 15th century. Many types existed, people had them hanging around their necks on a string or a chain. The idea of this particular sundial comes from the famous astronomer, Tycho Brahe. His book Astronomiae Instauratae Mechanica you can order on our website.