After their first rush, finding that the white men were on the alert, the blacks withdrew some distance, where their spears and arrows were not so effective. Our friends, including Andy Foger, and the German, kept up a hot fire whenever a skulking black form could be seen. But, though the danger from the spears and arrows was less, a new peril presented itself. This was from the blow guns. The curious weapons shot small arrows, tipped with tufts of a cottony substance in place of feathers, and could be sent for a long distance. The barbs were not strong enough to pierce the tough fabric of the gas bag, as a spear or arrow would have done, but there was more danger from them to our friends who were on deck. "Those barbs may be poisoned," said Mr. Durban, "and in case any one is wounded, the wound, though it be but a scratch, must be treated with antiseptics. I have some." This course was followed, the elephant hunter being wounded twice, and Andy Foger and Mr. Damon once each. There was not a native to be seen now, for they were hiding behind the trees of the jungle, but every now and then a blowgun barb would whizz out of the forest. Finally Mr. Durban suggested that they erect improvised shelters, behind which they could stand with their rifle, and breastworks were made out of packing boxes. Then our friends were comparatively safe. But they had to be on the alert, and it was nervous work, for they could not tell what minute the blacks would rush from the jungle, and, in spite of the fire from the electric rifle and other guns, overwhelm the ship. It was very trying to Tom and Ned, for they had to work hard and rapidly in the close engine room. The sweat dripped down off them, but they kept at it. It was three hours before the broken cylinder was removed, and it was no light task to put in the other, for the valves had to be made very tight to prevent leakage. The two lads stopped to get something to eat, while the guards kept sharp watch against a surprise. At intervals came a flight of barbs, and occasionally a black form could be seen, when it was instantly fired at. Several times the barbaric noise of the tom-toms and war drums, with which the shouts of the natives mingled, broke out deafeningly. "Think you can repair it by night?" asked Mr. Durban anxiously of Tom. "I hope so," was the response. "Because if we have to stay here after dark--well, I don't want to do it if I can help it," finished the hunter. Neither did the young inventor, and he redoubled his efforts to make the repairs. It was getting dark when the last belt was in place, and it was high time, too, for the natives were getting bolder, creeping up through the forest to within shooting distance with their arrows and spears. "There!" cried Tom at length. "Now we'll see if she works!" Once more he pulled the starting lever, and this time there was the welcome hiss of the gas. "Hurrah!" cried Ned.