The period of Fatih Sultan Mehmet (1451-1481) was a period of significant developments in ball casting technology for the Ottoman Empire. With the establishment of Tophane-i Amire, the Ottoman artillery has become more institutional. During this period, mobile cannon foundries and two-piece large siege cannons were built. The Ottomans knew and used mold technology well and used the ideal bronze mixture in ball casting. The foundries where the balls were cast were four-cornered structures covered with pedavra board, with honey barrels filled with water. In ball casting, the molds were formed in large pits, the inner and outer shape of the ball was given shape by molds. The ball casting was done with special ceremonies. Fatih Foundry, located in Demirköy, was established to meet the needs of the Ottoman army with cannon and cannonballs. The cannons were usually made of bronze, and large cannonballs could be fired up to a distance of 2 km.  Later, cannonballs fell out of use when artillery shells were invented that could carry explosive mortars on their own and create more effective destruction by exploding at the target they hit.