at 12:00, 2:00, 4:00, 8:00 and 10:00 with index markers at all remaining hour positions. Stationed between 4:00 and 5:00 is a date window complication  (less)

at 12:00, 2:00, 4:00, 8:00 and 10:00 with index markers at all remaining hour positions. Stationed between 4:00 and 5:00 is a date window complication  (less)

at 12:00, 2:00, 4:00, 8:00 and 10:00 with index markers at all remaining hour positions. Stationed between 4:00 and 5:00 is a date window complication  (less)

at 12:00, 2:00, 4:00, 8:00 and 10:00 with index markers at all remaining hour positions. Stationed between 4:00 and 5:00 is a date window complication  (less)

get you noticed. 42 mm 3-hand an  (less)

169 galaxies. Revolving in real-time, the dial displays an always accurate display of the stars and the sun. This powerful timepiece measures: Equinox Indications, Sunrise & Sunset. Daily Duration of Sunshine, Meridian, Ecliptic, Celestial Equator, Boundaries of Constellations, and much more ? it is an ?Astronomical Diagram from the Earth?. A beautifully detailed representation of space, The Astrodea Celestial Watch is packaged in a presentation box that includes a convenient 10x magnifier for close-up viewing. Limited edition and made in Japan of a stainless steel case, back and bracelet with a 42.5mm case diameter. The crystal is made of anti-reflective Sapphire. All the great voyagers in the age of exploration navigated with the Astrolabe, including Columbus, Magellan, and Drake. About 1391 Chaucer wrote his Treatise on the Astrolabe for his son. All scientific texts were written in Latin, so that scholars everywhere could read them. But Chaucer's son was too young at 10 to read Latin, so Chaucer's instructions to his son became the first scientific text written in English. The primary use of the mariner's Astrolabe was to find the latitude of a ship at sea. In use, the Astrolabe a mariner would use is suspended (above eye level) and the altitude of the sun or a star above the horizon is measured using a rotating disc. The measurement is taken when the sun or star is at its maximum altitude. The star's declination of the sun's declination for the day can be found from an almanac. The latitude is then found by solving the equation latitude=(90 degrees - measured altitude)+declination. The term (90 degrees - altitude) is called the zenith distance. Since it is often very difficult to determine exactly when the sun or a star is exactly north or south, the navigator would usually take several measurements before and after when the sun or star is on the meridian and use them to estimate the correct zenith distance. The mariner's Astrolabe is not a very accurate navigational instrument and errors of several degrees in latitude were common.  (less)