four o'clock
This work occupied them until midnight , and four large trees were thus prepared and lashed together , and one , wading in the water along the beach , using a pole , the other , with the rope , they held it within poling distance of the shore . In this manner the logs and detached pieces were floated down to the mouth of the stream , and having tied the small raft to the stern , it was finally poled across and landed at the water 's edge not far from the wagon . It was fortunate that the water was shallow and that the beach was shelving at this point , as it materially aided in effecting the launching . The moon went down before four o'clock that morning , and the yaks were yoked up and led to the river . When Harry returned he was surprised at what he saw in their camp . The Professor and George had been at work also . Several uprights had been put up on the side of the wagon facing the besiegers , and over this had been stretched an old canvas and parts of such goods as could be dispensed with , so as to imitate the wagon , as nearly as possible .