Reise in die Aequinoctial-Gegenden des neuen Continents. Band 4.

A travel narrative records an expedition up a riverine channel that links two major basins, describing the route, river widths, currents and the navigational difficulties posed by humid, cloudy weather that interfered with astronomical observations. The text combines precise geological observations of granitic outcrops and quartz veins, botanical and climatic notes, descriptions of local mission settlements, and practical measurements of channels and rapids. Field observations and reflected reasoning are used to explain how channel morphology, multiple river rills and regional topography can produce natural bifurcations that establish a navigable connection between adjacent river systems.