The fortification walls have been provided embrasure and merlons. A fireplace in the wing heated the hall, with its splayed window embrasure. The centre gun embrasure was converted to a doorway. During this period, Totten invented an iron-reinforced embrasure for cannon. Frankish window built from what once was an embrasure. Only the northern and southern fortification walls have been provided embrasure. The square frame fit snugly into the embrasure and was attached by hinges and bolts. There is a very large forward embrasure. Some have a low entrance that allows an extra embrasure above. He then threw his body at the embrasure. It was surrounded by a similar square frame, which fit tightly into the embrasure. The four short walls each have a single embrasure. The tunnellers realised that they could use the shaft as an embrasure for a gun. The door in these variants is offset to accommodate the fifth embrasure. The other walls vary from (), each having a single embrasure.