earlier). Also Copernicus followed the inductive reasoning while Ibn al-Shatir followed the Zij traditions. A Byzantine manuscript containing a solar model diagram with a second epicycle, was discovered to have been in Italy at the time of Copernicus. The presence of this eastern manuscript containing the ideas of Islamic scholars in Italy provides potential evidence of transmission of astronomical theories from the East to Western Europe. Instruments The idea of using hours of equal time length throughout the year was the innovation of Ibn al-Shatir in 1371, based on earlier developments in trigonometry by al-Battānī. Before the Islamicate scholar created the improved sundial, he had to understand the sundial created by his predecessors. The Greek had sundials too, but they had nodus-based with straight hour lines which meant that the hours in the day would be unequal (temporary hours) depending on the season. Each day was split into twelve equal segments which meant that the hours would have been shorter in the winter and longer in the summer due to the activity of the sun. Ibn al-Shatir was aware that "using a gnomon that is parallel to the Earth's axis will produce sundials whose hour lines indicate equal hours on any day of the year." His sundial is the oldest polar-axis sundial still in existence. The concept later appeared in Western sundials from at least 1446. Ibn al-Shatir also invented a timekeeping device called "Sandūq al‐Yawāqīt li maʿrifat al-Mawāqīt" (jewel box), which incorporates both a universal sundial and a magnetic compass. He invented it for the purpose of finding the times of prayers. The "Sandūq al‐Yawāqīt li maʿrifat al-Mawāqīt" had a moveable hole in it which allowed the user to find the hour angle of the sun. If this angle was suitable with the horizon, then the user could use it as a polar sundial. This device is preserved in the museum of Aleppo (largest museum in the city of Aleppo, Syria). He also created a sundial which was placed on top of the Madhanat al-Arus (The Minaret of the Bride) in the Umayyad Mosque. The sundial was created on a slab of marble which was approximately 2 meters by 1 meter. The sundial being engraved on the marble was so that Ibn al-Shatir could read the time of the day in equinoctial (equal times) hours for the prayer times. This sundial was later removed in the eighteenth century and