Made of brass, it is signed by its artist, Husain b. Ali and dated back to around 1310 AD. 17 The front part of the astrolabe is made up of four plates that serve as a projection of celestial bodies into the sky. Also on the front of the instrument are the lines used for calculations and marked for each line of latitude. The astrolabe network shows 21 stars with pointers. The reverse shows a shadow square which is used to measure heights for other necessary intangible calculations. Although this astrolabe possesses a shadow square which is quite common for Islamic astrolabes, not all possess it. On the back there is also the scale essential for calculating the months and days of the calendar as well as for the orientation of the Qiblah.18 Compared to the oldest known existing Islamic astrolabe, Ali's appears to be in much better condition. This astrolabe, probably the earliest known example in possession, dates back to 9th century Iraq. Although there is the only other example of an astrolabe that may be older than this one, its whereabouts remain unknown as it was lost in the 2003 Baghdad Museum robbery. Although it dates back to Iraq, this astrolabe was found near the waters of the Malaysian coast, suggesting that it may have been used for trade excursions to China from Iraq.19 In current times, also as a tool