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  • It consists on a Perpetual Moon phases calendar with a Tidal abacus or computer on the back. This instrument was conceived to address the need to predict the time of tidal changes. It draws on their intimate association with the rotation of the Moon, which influences the tides as it revolves around the Earth. Knowledge of the lunar phases has been of...

  • Only perpetual calendars meet the basic condition to permit the deduction of any essential data from any other data (year, month, week and day). However, all the analog perpetual calendars known are hardly perpetual since the limit of their calculations is about 50 years.  Our calendar starts at January 1, 1600, and ends at December 31, 2799. It is based...

  • This instrument is a reproduction based on two Gunter (E. Gunter, 1581-1626) quadrants made in the mid-eighteenth century. The original pieces, made by unknown English authors, are at the Greenwich National Maritime Museum, London. On the face side, the instrument presents a local height quadrant furnished with a pinule system for establishing the Sun’s...

  • In Europe, the astrolabe became the vital tool for astronomers, astrologers and surveyors until the end of the 17th century, when it was replaced by more precise instruments. In the Arab world its use continued until the 19th century. This Plansiferic Astrolabe is based on an instrument made by German manufacturer. G. Hartmann which can be found at the...

  • This nocturnal watch ––horologium nocturnale–  is an astronomical instrument used to measure the time through the observation of the Pole Star and the position of brigth stars in the celestial sphere.  This nocturnal is a reproduction of the one made in 1570 by Girolamo della Volpaia  (currently at the Galileo Museum in Florence, former History of...

  • Although known as the astronomical ring, it is principally employed as an ecuatorial solar universal quadrant. Its use was widespread during 18th century.  It is composed of a ring that can be adjusted to various latitudes, a meridian ring showing the latitude scale, a moveable hour ring and a central, grooved bar that is graduated for the months of the...

  • This scientific toy with animated images also relies in retinal persistence to make us believe we are seeing images in motion. The praxinoscope was patented by the Frenchman Emile Reynaud in 1877, who was looking to overcome the deficiencies of the zoetrope, the most popular at the time. His apparatus was the first to eliminate the distorted view of the...

  • From first scientific toys that used animated images to modern movies, retinal persistence has been fundamental to fooling the mind into believing that a series of static images are in motion. In 1834, the English mathematician George Horner proposed a practical apparatus based on the phenakistoscope of Plateau and Stampfer (1830). It eliminated the need...

  • The Scottish mathematician John Napier (1550-1617) invented this abacus. In 1617, the year of his death, Napier published in Edinburgh a short work in Latin titled Rabdologiae, in which he dealt with products and quotients of numbers. In the book, Napier describes a series of rods which he had invented –later known as Napier’s bones– which, placed in...

  • This piece is a sundial for prayers/mass hour. The original jewel, probably made on the 10th century, was found at Canterbury Cathedral, UK.  The dial was updated for London’s   latitude 50º. The dial must be hanged, facing the sun to find the hours like any other altitude sundial, introducing the little bar on the corresponding Month´s hole....

  • It´s the miniature version of our H36.  This planisferic astrolabe was developed after the one made by Diya´al Din Muhammad (Lahore, 1647).  The original piece could be found at the Adler Planetarium & Astronomy Museum, Chicago.  The stars on its rete and all other calculus were updated to make it functional. It was set for latitude 22º (Mecca)....

  • The piece is a reproduction of an instrument dated 1570 and signed by Humphrey Cole. This instrument is in the British Museum, London. The original piece has two faces, one of which is this nocturnal. This nocturnal watch is an artifact used to obtain the time at night using the fixed stars in the sky. This instrument appeared at the beginning of the...

Showing 1 - 12 of 21 items