The Karmakars used to be blacksmiths by profession. Over time, the Karmakars have produced engineering masterpieces. In 1637, Janardan Karmakar (Blacksmith) of Sylhet built the great gun of
Murshidabad, the
Jahan Kosha Cannon 'Destroyer of the World', which is in length and weighs around 7 tons. Another grand cannon named
Dal Madal Kaman was built by Jagannath Karmakar in 1565 for the kingdom of
Mallabhum. In the late 18th century,
Wiiliam Carey of serampore teamed up with
Panchanan Karmakar to make Bengali wooden types. == Notables ==