Rockets as an early weapon of destruction were invented in China in the 11th century and the Mongols took them to Europe. Mughals used rockets in the 15th and 16th century, but these fell into disuse with the increasing accuracy and power of the artillery. This article focusses on an interesting episode of the re-emergence of rockets in India in the 19th century.
Hyder Ali, a bold officer in the army of the raja of Mysore, and his son Tipu Sultan, used rockets frequently in various battles against the British, including the four Anglo-Mysore wars. The rockets consisted of a metal cylinder containing combustion powder, which was tied to a long bamboo pole or sword that provided the required stability to the missile. They were similar to the small rockets we still use in diwali.
These rockets had higher thrust and range than anything the world had known. These rockets weighed 3.5 kg, and were tied to 3 meter long bamboo poles. Guess what was extraordinary about the construction of these rockets? The propellant? No, it was standard gunpowder. The aerodynamics? No, there was nothing unusual about it. What made these rockets extraordinary was the material employed for casing the cylinder.
The iron found in India was better than anywhere in Europe. Mysoreans used iron for casing instead of wood. The use of iron increased the bursting pressures, which permitted the propellant to be packed to greater densities. This is why these rockets performed outstandingly. Hyder and Tipu achieved their famous victory in the battle of Pollilur, and these rockets played a major role.