Their leader, a tall, thin savage of exceptionally repulsive appearance, motioned with his fingers to his thick lips for absolute silence among his followers.
Clutching their great broad-headed war-spears the next moment the savages slipped into the forest in the direction the Arab and his band had gone. Steadily they advanced with the quiet stealthy tread of panthers on the track of their prey.
CHAPTER XIII
GORILLAS—AND AN AERIAL TOW-LINE
The mystery of the man on the hill bade fair to be an unsolved one, for although the boys watched for some time with considerable anxiety he did not reappear. This feature of the incident set them to comparing notes and they found that their impression of the apparition differed considerably. Both Frank and Harry were ready to swear that he was a black man, while Ben Stubbs was equally convinced that his skin was of a reddish hue. All three, however, agreed that he was weaponless so far as could be seen, and his attitude appeared to be more one of interested curiosity than of actual hostility.
"Well, there's no use wasting time in speculation," said Frank at last, "more especially as it does not look as if we can get any nearer to solving the problem in that way. The thing to do now is to get at the ivory and that as quickly as possible. If that man is the forerunner of a band that means to attack us, it is all the more reason that we should get a move on."
"Right you are, Captain," assented Ben, "and here goes!"
With a mighty swing of his pick the former prospector dislodged a pile of the rough stones of which the cairn was composed and the boys, too, laid on with a will. In an hour or so all that was left of the once lofty cairn was a few big rocks.
Excitement ran fairly to fever heat as the last obstruction that lay between the adventurers and the ivory hoard was cast aside.