History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c13.s3.11

v1.c13.s3.11

During the Mughal period the casting technology was much developed and it was used for casting huge Guns like Malikai Maidan. The mould for this heavy and beautifully designed gun was prepared below the ground level by using moulding sand mixture and sweep moulding process. A solid core prepared from rice paddy, sand and clay mixture or sand and molasses mixture was first dried and baked and then fixed in the centre of the mould to make the bore hole of the gun. In the absence of heavy crane and machinery for handling such large amount of molten bronze the melting furnace was constructed at a higher level. The molten metal was melted in a large shaft or crucible prepared insitu, and when it had reached the desired composition and fluidity the molten metal was poured into the mould by preparing a channel connecting the crucible to the mould and piercing a hole in the crucible wall. After the casting had solidified over a period of few days the mold was broken to take out the casting and finish it by cleaning, chiselling and polishing. In a like manner huge cannon balls were cast either in non-ferrous metals or cast iron. This industry has also faced a set back during the British Rule.