"The black troops have more spirit than the Egyptians, but they are not so useful in clearing channels, as they are bad swimmers. They discovered to-day a muddy spot where they had a great hunt for fish, and succeeded in capturing with their hands about 500 pounds weight of the Prolypterus, some of which were above four pounds. We caught for ourselves a number of very delicious boulti (Perca Nilotica) with a casting-net. "March 15.--Having probed the marsh with long poles, I found deep water beneath, which denoted the course of the sub-vegetal stream. All hands at work, and by the evening we had cut a channel 300 yards in length. The marsh swarms with snakes, one of which managed to enter the cabin window of the diahbeeah. The two steamers, now far astern, have become choked by a general break up and alteration of their portion of the world. The small lake in which I left them is no longer open water, but has become a dense maps of compressed vegetable rafts, in which the steamers are jammed as though frozen in an ice-drift in the Arctic regions! There is much work required to clear them. The only chance of progress will be to keep the entire fleet in compact line so as to push through a new channel as quickly as it is made. I shall send back the wood tender, if possible, from this spot with a letter to stop Mr. Higginbotham should he be south of the Sobat, as it will be impossible for him to proceed until next season. Many of the men are sick with fever, and if this horrible country should continue, they will all sicken. "March 16.--I went back in a rowing boat, accompanied by Lieutenant Baker, to the two steamers which we found stuck fast in the drift rafts, that had closed in upon then. Many men are sick--all are dispirited; and they worked badly. Having worked all day, we returned at 6.30 p.m., to my diahbeeah, having the good fortune to shoot seven ducks by a family shot upon a mud bank on the way home. "I found that the main body under the colonel, Raouf Bey, had completed the channel about 900 yards long to lake No. 3. I ordered sail to be made immediately, and after five hours' hard work, as the channel was already beginning to close, we arrived in the open lake at 11.15 p.m., in which we found the fleet at anchor. "March 17.--The lake is about 2 1/2 miles long, and varies from 150 to 300 yards in width, with a mean depth of ten feet. I sent men ahead in the boat to explore the exit; they now report it to be closed by a small dam, after which we shall enter another lake. Thunder and clouds threatening in the southeast.