It may be considered a version of a volley gun.[188] One such gun he developed was a seventeen-barrelled cannon fired with a matchlock.[189] Seamless celestial globe: It was invented in Kashmir by Ali Kashmiri ibn Luqman in 998 AH (1589–1590), and twenty other such globes were later produced in Lahore and Kashmir during the Mughal Empire. Before they were rediscovered in the 1980s, it was believed by modern metallurgists to be technically impossible to produce metal globes without any seams.[190]