The Dyoor and the Bongo appear almost equally ignorant about charcoal-burning. They understand very little about the exclusion of air from the furnaces, or of burning their wood in piles: their science seems limited to the combustion of small fragments heaped up over one another till the fire below them is choked, or subdued by pouring water upon the top. I am not aware whether the other negroes have mastered the secret of charcoal-making; but if what has been said about the Dyoor holds good about Africa in general, it accounts at once for the remarkable fact that in spite of the abundance of the crude material, iron is so little employed. There is a universal absence of lime, so that stone erections are quite unknown. If a comparison might be instituted, I should say that in Africa iron might be estimated to have a value about equivalent to copper with us, whilst the worth of copper would correspond to that of silver. [Illustration: DYOOR VILLAGE IN WINTER.] [Sidenote: DYOOR HUTS.] For fifteen years have the Nubians now been brought into contact with this region, but they have never taught the natives either the way of making bricks or any intelligent conception of the use of charcoal. Themselves too lazy to improve the treasures which a bountiful Nature has flung amongst them, they are too idle and too indifferent to stimulate even the people they have subjugated to put forth any energy at all. And this is but one proof out of many of the demoralising tendency of Islamism, which would ever give a retrograde movement to all civilisation. Throughout Africa I have never come across a tribe that has not adopted a mode of building huts which, alike with respect to exterior and interior, is not peculiar to itself. The huts of the Dyoor do not resemble the mushroom shapes of the Shillooks, nor are they like the substantial huts of the Dinka, massive and distinguished by small outbuildings and porches. Again, they could not for a moment be mistaken to be dwellings of the Bongo, because they have no straw projections about the top of the roof. In a general way they are a yet more simple and unadorned construction—not that they are destitute of that neat symmetry which seems to belong to all negro dwellings. The roof is a simple pyramid of straw, of which the section is an equilateral triangle, the substructure being all of wickerwork, either of wood or bamboo, and cemented with clay.