We left the Esmeralda mission on the 23rd of May. We were not exactly ill, but emaciated and weak thanks to the torment of mosquitoes, the bad food and the long journey on that narrow and damp pirogue. We did not go further up the Orinoco than the mouth of the Guapo; had we wanted to reach the Orinoco sources we would have gone beyond this point, but private travelers are not authorized to leave pacified areas. From the Guapo river to the Guaharibo cataract there are only 15 leagues. But the cataract is crossed by a liana bridge where Indians armed with bows and arrows stop whites from entering their lands. Up to the present time the Orinoco posed two distinct problems for geographers: its sources, and the nature of its communications with the Amazon. This latter was the aim of our journey.