Frobenius, in describing the objects discovered by this expedition, says: "The substance of the pots is a sort of cement or stoneware. They are from fourteen to twenty four inches high and from three and three quarters to sixteen inches in diameter; they are generally uniform. The aperture is at the under and upper ends of the walls from about three quarters to one and a quarter inches thick. The upper of these portions is covered with an irregular glaze, varying from one thirty sixth to one eighteenth of an inch thick inside. They were similarly glazed outside as the edges proved, but this has perished. A convexly carved plate or cupola in which there are three or four holes for finger holds seem to have been lids. Inside the pots are glass beads, rings, irregular bits of glass tubing, and always at the bottom a mass of fused bits of glass from one eighth to one quarter of an inch in depth. The colors of the beads and the glaze on the jars vary from light green, greenish white, dark red, brown and blue." Frobenius, commenting upon these finds, concludes that "the great mass of potsherds, lumps of glass, heaps of slag, etc., which we found proves at all events that the glass industry flourished in this locality in ages past. It is plain that the glass beads found to have been so common in Africa were not imported, but were actually manufactured in great quantities at home."[35] In addition to these objects of stoneware and glass, there were a large variety of terra cotta objects which range from the "simplest little pots and saucers to the most artistic shapes and portraits." To appreciate the real significance of these objects in view of the inability to see the originals themselves, one should make a special effort to see the drawings and photographs of these objects as contained in Frobenius's _Der Afrika Sprach_, or its English translation, _The Voice of Africa_. Accompanying these illustrations there are a few brief descriptions of the more important objects. There is, for instance, "a specimen which seems to be the mouth or collar of an urn. On its inner edge there is a mouth below, an ear on either side, and a pair of eyes.... It looks as if this might have been a portion of a tube which might have been put over a grave, through which offerings might have been made to the dead beneath."[36] This explanation for the original purpose of this object is very plausible, as a study of the burial customs of various parts of Africa will show.