"...The city of Ava is surrounded by a brick wall fifteen and a half feet in height, and ten feet in thickness: on the inside of which there is thrown up a bank of earth forming about an angle of forty-five degrees: on the top of this bank there is a terre pleine, in some places, of a good breadth, but in others, so narrow as scarcely to admit the recoil of a gun. The parapet of brickwork is four and ahalf feet in height, and two in thickness, measured across the superior slope..."