...t Caswell, below Wilmington, has been casemated with iron; but can it withstand elongated balls weighing 480 pounds? I fear not. There are, however, submarine batteries; yet these may be avoided, for Gen. Whiting writes that the best pilot (one sent thither some time ago by the enemy) escaped to the hostile fleet since Gen. Smith visited North Carolina, which is embraced within his command. This pilot, no ...