midnight
To the north of them , less than a quarter of a mile away , was a quantity of small timber , and the Professor suggested that it would be advisable to go a considerable distance so the cutting of the logs would not be heard by their watchers . They pushed the raft silently across the water , and drew it up for safety , and then stole down to the water 's edge to make their way beyond the sight of the savages on the opposite side . All along the shore advantage was taken of every piece of wood available to serve as a floating structure , and when the wood was reached a few of convenient size were selected and cut up into lengths which would enable them to be readily rolled down to the river . 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 .