Cannons were installed at each of the three British positions: a 32-pounder at the main camp, along with a 6-pounder brass gun, two 32-pounders at the main gun battery, and the 18-pounder at the forward gun battery.
The cannon were cast-iron muzzle loaders, typical of that time period. The cannonballs were solid cast iron, weighing up to 14.5 kg (32 pounds). To fire, the gunner loaded a fabric powder cartridge down the muzzle, then the shot, and a wad to hold it in place. A wire pricker was inserted into the vent to prick the charge, which was filled with gunpowder. A gunlock or a slow match was held at the vent to fire the gun.1 Although not very accurate or reliable (by modern standards), cannon like these were very good at smashing field fortifications.
1 Jones, G. (senior editor). 2012. The Military History Book: The Ultimate Visual Guide to the Weapons that Shaped the World. Dorling Kindersley, London. p. 198