In case of a mutiny, the soldiers could sweep the prison from end to end with grape shot.

Such fresh air as there was, filtered through the loopholes, and came, in somewhat larger quantity, through a wind-sail passed into the prison from the hatchway.

But the wind-sail, being necessarily at one end only of the place, the air it brought was pretty well absorbed by the twenty or thirty lucky fellows near it, and the other hundred and fifty did not come so well off.

The scuttles were open, certainly, but as the row of bunks had been built against them, the air they brought was the peculiar property of such men as occupied the berths into which they penetrated.
These berths were twenty-eight in number, each containing six men.

They ran in a double tier round three sides of the prison, twenty at each side, and eight affixed to that portion of the forward barricade opposite the door.