sentences:  A lack of any form of defence however, led to the creation of the Royal South Australian Volunteer Militia, consisting of an infantry company and two cavalry troops, in 1840, although it was disbanded in 1851; for the final six years of its existence it had been a force that had existed on paper only.The first artillery pieces arrived in South Australia aboard "Buffalo", which landed two 18-pound cannons, but initially there were no moves to form an artillery unit, so the guns were operated by Royal Engineers.In 1844 a request for further pieces was sent to the British government and two years later two light 6-pounders, two 12-pounder howitzers and two Cohorn mortars arrived with an ammunition store of about 500 rounds for each weapon type.