"'Beads of different kinds and colors, put up and labelled, so that the contents of each package can be known at a glance. Every tribe of negroes in Africa has tastes of its own, and beads that find ready circulation in one region are worthless in another. "'Cotton cloths of different kinds, white, gray, striped, and in all the colors and combinations of the rainbow. "'Gaudy handkerchiefs, and the gaudier they are the better for purposes of trade. In packing them for transportation they should be placed in the bales with the cloths, which should also be made up in assorted lots, so that when a bale is opened several kinds of goods may be displayed. "'Pocket-mirrors, copper wire, in rolls and of different sizes; small tools, fish-hooks, cheap watches, brass jewellery, mechanical toys, sleigh-bells, knives, hatchets, and other edged tools that can be easily carried and handled.'" "Something to amuse the natives is next on the list," the Doctor remarked, as Frank paused for a moment, "and it is often of great advantage to amuse them." "'A dozen musical boxes of small size, and one large one, playing several tunes,'" continued Frank, reading from the paper. "I suppose the small ones are for presents," said Fred, "and the large one is to be exhibited on great occasions, when we have company?" "Exactly so," replied the Doctor; "it will be a convenient means of entertaining savages, especially when we cannot converse with them. You observe that I have included in the list of desirable things a magic-lantern and a telephone, with half a mile of wire and all the apparatus complete. They are easy to carry, and their performances will be as interesting as those of the music-boxes." "'Cloth, beads, caps, tools, toys, and trinkets are what we need for traffic with the natives and paying our expenses,"' read Frank as he turned the sheet of paper. "Now we come to what we want for our own use." [Illustration: CAMP AND CARAVAN.] "'Tea and coffee, in air-tight cans of not more than a pound each, so that they will not be spoiled by the climate: preserved meats and vegetables, sugar, spices, pepper, sauces, vinegar, matches, soap, candles, and a few other things, the fewer the better. Everything we carry must be enclosed in tin cases, so as to protect it from dampness, as the climate of Central Africa is ruinous to all articles that absorb moisture. "'Rifles, shot-guns, and pistols, with plenty of ammunition. The rifles and shot-guns of the Remington system, using fixed ammunition.'" One of the boys asked what was meant by "fixed ammunition." "The cartridges are made up," the Doctor explained, "and are all ready for use. The powder is in a shell of copper or brass, with the explosive cap in one end and the bullet or shot firmly wedged in the other. The cartridges are impervious to water, and can be kept a long time without detriment."