Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

1834. LEVEL OF RIVER — BONES. 355 Reference to the accompanying plan will shew our position when we halted, and I decided to i-eturn, not having explored, I should think, more than one-third of its course. At that place the level of the river was found to be four hundred feet higher than that of the sea at the entrance ; and as the distance is about two hundred miles,* the average descent or fall of the water must be near two feet in a mile, which, I apprehend, is unusually great. I could not, indeed, believe that the compu- tation and data were correct, until after repeated examination.-f- Two barometers were used at the river-side, and a very good one was carefully watched on board the Beagle.J Certainly, the rapid descent of the river, in many places, was such, that even to the eye it appeared to be running down-hill ; and this remark Avas often made in the course of our journey. Two days before we reached our westernmost point, many traces of an old Indian encampment were seen ; but excepting at that place and at the spot Avhich we passed on the 22d, no signs of inhabitants were any where found. Scarcity of pas- ture, and the badness of the ground for their horses' feet, must deter Indians from remaining in this neighbourhood; but that they frequently cross the river, when travelling, is well known. The quantities of bones heaped together, or scattered near the river, in so many places which we passed, excited conjec- tures as to what had collected them. Do guanacoes approach the river to drink when they are dying .? or are the bones remains of animals eaten by lions or by Indians ? or are they washed together by floods ? Certain it is they are remarkably numerous near the banks of the river ; but not so elsewhere. I can hardly think that the guanaco is often allowed to die a natural death; for pumas are always on the alert to seize invalid stragglers from the herd. At night the guanacoes choose the clearest places for sleeping, lying down together like sheep ; and in the day they avoid thickets, and all such places as might * Following- the course of the river. t The data will he found in the Appendix. X At the level of the sea, 2 a2