Chapter VII. AN UNSEEN HUNTER.They calculated that they had come ten or twelve miles from the place at which they built the raft, while the damp salt breeze blowing from the south showed them they were near the ocean. Concluding that large bodies of water must be very much alike on all planets, they decided to make for a range of hills due north and a few miles off, and to complete the circuit of the square in returning to the Callisto. The soft wet sand was covered with huge and curious tracks, doubtless made by creatures that had come to the stream during the night to drink, and they noticed with satisfaction as they set out that the fresher ones led off in the direction in which they were going. For practice, they blew off the heads of the boa-constrictors as they hung from the trees, a

