About half way up Cape Verd is a large lake, the water of which is brackish, though formed by a rivulet which is perfectly fresh. It is difficult to explain the cause of this singularity. Some suppose that the bottom of the lake consists of a nitrous earth, which communicates its flavour to the water; while others think, and perhaps with more reason, that the sea water filtrates through the ground, and mixes with that of the lake. But whatever may be the cause, it is remarkable that the water agrees equally well with sea and river fish. The negroes take immense quantities of fish between Capes Verd and Manuel, where the lake empties itself into the sea; and the vast flocks of birds, which live on its banks, also devour quantities of fish. Amongst the birds is a species which seems to belong to the falcon tribe: they have a brown plumage, with some white feathers at the neck and extremities of the wings . Their beak is thick and curved like a sickle, so that the fish which they take cannot escape. They have short thighs and claws; and the latter are armed with strong and sharp nails. They fly easily, and keep themselves for a considerable time on the surface of the water with the head inclined. When a fish appears they dart upon it, and carry it off to devour amongst the reeds. They have been sometimes shot, but they cannot be eaten, as their flesh has such a rank and fishy taste, and is full of oil. Near this lake, and in several parts of the route lately mentioned, are numbers of trumpet birds, whose notes resemble the sound of that instrument. They are black, and of the size of a turkey-cock, to which they are nearly similar in shape. Their lower beak is hollow and sonorous; and it is by this that they produce the sound described.