The prison was about fifty feet long and fifty feet wide, and ran the full height of the 'tween decks, viz., about five feet ten inches high.

The barricade was loop-holed here and there, and the planks were in some places wide enough to admit a musket barrel.

On the aft side, next the soldiers' berths, was a trap door, like the stoke-hole of a furnace.

At first sight this appeared to be contrived for the humane purpose of ventilation, but a second glance dispelled this weak conclusion.

The opening was just large enough to admit the muzzle of a small howitzer, secured on the deck below.