16 FOUL CANAL. The cramped passage widens here. A channel of foul water runs down the center of the wide east-west passage, a lip of dry walkway is on the north and south portions, about a foot higher than the water line. The ceiling height is seven feet above the water line. The passage has the same configuration as far as Area 18 to the west, as well as to Area 28 to the east and the side passage leading to Area 31.