Board of Ordnance limestone boundary stone no. 3 as annotated on the 1859 War Office plan of the ordnance tower on Shenick's Island. This boundary stone to the SW of the Martello Tower was one of 10 stones demarcating a circular area aound the base of the tower which belonged to the Board of Ordnance. This circular piece of land was accessed by a War Department Right of Way to the SW which was delimited by a series of unmarked granite stones. The land amounting to half an acre was purchased in 1806 by the War Office from Hans Hamilton (c. 1758-1822) son of James Hamilton of Sheephill & Holmpatrick. According to Wikipedia: 'The Board of Ordnance was a British government body, its headquarters in the Tower of London. Its primary responsibilities were 'to act as custodian of the lands, depots and forts required for the defence of the realm and its overseas possessions, and as the supplier of munitions and equipment to both the Army and the Navy. In 1855 it was disbanded and replaced by the War Department'.