Book 2
8
In consequence of the frequent sorties of the enemy, it was noticed by the legionaries who were conducting operations on the right that it could be a great protection to them if they made there a tower of brick under the wall to serve as a stronghold and place of retreat. This they constructed at first of low elevation and small size to meet sudden sallies. To this they used to retire; from this shelter they fought if a stronger assault pressed them; from this they issued forth to repel and pursue the foe. Its dimensions were thirty feet each way, but the thickness of the walls was five feet. But afterwards, as experience is the guide of all conduct, by applying their wits they discovered that it could be of great service to them if this tower were raised to a height. This was accomplished in the following manner.
