After Tom had shot several other of the illuminated charges into the jungle, to see if he could discover any more lions, but failed to do so, he and his friends returned to the anchored airship, amid the murmured thanks of the Africans. Bright fires were kept blazing all the rest of the night, but, though lions could be heard roaring in the jungle, and though they approached alarmingly close to the place where our friends were encamped, none of the savage brutes ventured within the clearing. With the valuable store of ivory aboard the Black Hawk, which was now completely repaired, an early start was made the next morning. The Africans besought Tom and his companions to remain, for it was not often they could have the services of white men in slaying elephants and lions. "But, we've got to get on the trail," decided Tom, when the natives had brought great stores of food, and such simple presents as they possessed, to induce the travelers to remain. "Every hour may add to the danger of the missionaries in the hands of the red pygmies." "Yes," said Mr. Anderson gravely, "it is our duty to save them." And so the airship mounted into the air, our friends waving farewells to the simple-hearted blacks, who did a sort of farewell war-dance in their honor, shouting their praises aloud, and beating the drums and tom-toms, so that the echoes followed for some time after the Black Hawk had begun to mount upward toward the sky. The craft was in excellent shape, due to the overhauling Tom had given it while making the repairs. With the propellers beating the air, and the rudder set to hold them about two thousand feet high, the travelers moved rapidly over clearings, forests and jungles. It was agreed that now, when they had made such a good start in collecting ivory, that they would spend the next few days in trying to get on the trail of the red pygmies. It might seem a simple matter, after knowing the approximate location of the land of these fierce little natives, to have proceeded directly to it. But Africa is an immense continent, and even in an airship comparatively little of the interior can be seen at a time. Besides, the red pygmies had a habit of moving from place to place, and they were so small, and so wild, capable of living in very tiny huts or caves, and so primitive, not building regular villages as the other Africans do, that as Ned said, they were as hard to locate as the proverbial flea. Our friends had a general idea of where to look for them, but on nearing that land, and making inquiries of several friendly tribes, they learned that the red pygmies had suddenly disappeared from their usual haunts. "I guess they heard that we were after them," said Tom, with a grim smile one day, as he sent the airship down toward the earth, for they were over a great plain, and several native villages could be seen dotted on its surface.