But after rest and food, he was ready to tackle the work again, and he took heart when he found that the negroes were much more amenable. The spirit of emulation he had excited among them lightened the task. Every man seemed anxious to win praise from the white man. The idea had got abroad among them that the exercises to which he put them were so much "white man's medicine," something that would have a mystic efficacy when they came in contact with the enemy. As this idea implied unquestioning faith, it was all that Challis required. He was careful not to keep them too long at one thing. When they had at last seized the idea of a straight line, though still far from successful in achieving it, he set the twenty selected spearmen to compete among themselves, and devoted his attention to the sixty less proficient. These he determined to turn into pikemen. He got them to cut longer shafts for their spear heads and to sharpen the lower end, so that by the close of the day they were provided with serviceable pikes eight feet long. The end of the day brought its disappointment. The messengers dispatched by the chief to neighbouring villages returned and reported the complete failure of their mission. Such was the universal dread of the Tubus that no chief was willing to send his men to encounter them. Not even the messengers' report of the lion-killing sufficed to overcome their fears. "They will sit on the fence," thought Challis. "If we have any success, they'll come tumbling over each other to help. Well, we haven't done so badly for the first day. I must make plans for to-morrow." He spent that night, not in the fœtid cave, but in the open, protected from wild beasts by a ring of bonfires. After all, he thought, they were too far from the Tubus' camps to attract attention. Next morning, after repeating the lessons of the previous day, and finding that the men gave much less trouble, he taught them how to extend, moving them up and down with fair success. With John's assistance, he got them to turn right or left at the word of command. At first they laughed so heartily at the sight of one another moving like teetotums that discipline was in danger of breaking down. Challis himself was amused, thinking how wrathful the loud-voiced drill-instructor at his old school would have been if the boys had taken their drill as lightheartedly as these negroes. But after a time they settled down to learn their new prescription in "white man's medicine," and made the proper movements with creditable smartness. The next operation was to form three sides of a square--their numbers did not suffice for a full square of any considerable size. This was difficult. "Do their minds work in curves?" thought Challis despairingly, as the men tended persistently to round the angles and join the ends of the lines.