Read it through once

Next morning I felt pretty rusty and low-spirited. We went booming along, taking a good many chances, for we were anxious to 'get out of the river' (as getting out to Cairo was called) before night should overtake us. But Mr. Bixby's partner, the other pilot, presently grounded the boat, and we lost so much time in getting her off that it was plain that darkness would overtake us a good long way above the mouth. This was a great misfortune, especially to certain of our visiting pilots, whose boats would have to wait for their return, no matter how long that might be. It sobered the pilot-house talk a good deal. Coming up-stream, pilots did not mind low water or any kind of darkness; nothing stopped them but fog. But down-stream work was different; a boat was too nearly helpless, with a stiff current pushing behind her; so it was not customary to run down-stream at night in low water.