"A trying suspense, to be passing a whole summer night on the brink of the black ocean, ready to take that plunge into it upon which Monsieur Gabelle had resolved! But, the friendly dawn appearing at last, and the rush-candles of the village guttering out, the people happily dispersed, and Monsieur Gabelle came down, bringing his life with him for that while" (p. 242).

In this passage, the "black ocean" represents the mob that has formed. Poor Monsieur Gabelle is the center of this mob. They want to see him dead, even though he was just doing his JOB. When I think of a "black ocean" I think of a storm at sea and waves crashing everywhere, with no escape. Monsieur Gabelle is in that position. He has no escape from this "storm" until the sun rises. The sun brings the end of the storm and in the morning, the sea is always calm, just like the people here are.