Jahan Kosha Cannon, Murshidabad

The Jahan Kosha Cannon, whose name means Destroyer of the World and which is also called the Great Gun, rests in the Topekhana of Murshidabad, about 400 m south-east of the Katra Mosque. The Nawabs kept their artillery here, at the gateway to their old capital, with the Gobra Nala, locally called Katra Jheel, guarding its eastern side. An inscription records that the gun was made at Dacca in 1637, in Shah Jahan's reign, at the instance of the Bengal subedar Islam Khan; the smith Janardan Karmakar made it under Daroga Shere Mohammad, with Hara Ballav Das supervising.

The gun is of ashtadhatu, an alloy of eight metals, weighs over 7 tonnes and measures 17 ft 6 in long; a single firing took 17 kg of gunpowder. It once lay on a wheeled carriage, and the roots of a peepal tree slowly raised it four feet off the ground. The wheels are lost, but the carriage ironwork and trunnions survive. The ASI maintains it.