“A clock measures time….and time is the most precious gift we are given.’
~Petr Skala -Prague’s clock master
For more than 600 years, one clock has been measuring the passing hours, noting when day turns to night as well as the position of the sun, moon and stars…Prague’s famed Astronomical Clock, the Orloj, in the city’s Old Town.
Perhaps no other clock better demonstrates the genius of the early pioneers of time keeping than the Orloj. Marking the minutes and hours is only one of the many measurements it provides. It tracks Old Bohemian time, when the new day began with sunset; Babylonian time, which tracks the day from sunrise to sunset; Central European time, which is marked with a distinctive hand in the shape of the sun; and Star time, measured by the way the stars appear to move because of the Earth’s rotation.
A calendar dial notes the days of the week, month and year, and a zodiacal ring shows the path of the sun and moon through the sky. But it is the astrolabe that is the heart of the clock’s mechanical operation. The apparatus, which tracks the position of the sun, moon and stars, has been an essential tool for astronomers and mariners dating back to antiquity.