would give free communication.
His calculations were made, of course, for the smaller craft of that
time.

The rivers belonging to the Caribbean system, all of which flow in a
northerly direction, are the Atrato, Bacuba, Sinu, Magdalena and
Zulia. The Bacuba, Suriquilla or Leon, is a small stream rising on the
western slopes of the Cordillera and flowing into the upper end of the
Gulf of Uraba. Like the Atrato it brings down much silt, which is
rapidly filling that depression. There are many small streams and one
important river, the Sinu, flowing into the sea between this gulf and
the mouth of the Magdalena. The Sinu rises on the northern slopes of
the Alto del Viento near the 7th parallel, and flows almost due north
across the coastal plain for a distance of about 286 m. to the Gulf of
Morosquillo. It has a very sinuous channel which is navigable for
small steamers for some distance, but there is no good port at its
outlet, and a considerable part of the region through which it flows
is malarial and sparsely settled. The most important rivers of
Colombia, however, are the Magdalena and its principal tributary, the
Cauca. They both rise on the high table-land of southern Colombia
about 14,000 ft. above sea-level--the Magdalena in the Laguna del Buey
(Ox Lake) on the Las Papas plateau, and the Cauca a short distance
westward in the Laguna de Santiago on the Paramo de Guanacas--and flow
northward in parallel courses with the great Central Cordillera,
forming the water-parting between their drainage basins. The principal
tributaries of the Magdalena are the Suaza, Neiva, Cabrera, Prado,
Fusagasaga, Funza or Bogota, Carare, Opon, Sogamoso, Lebrija and
Cesar, and the western the La Plata, Paez, Saldana, Cuello, Guali,
Samana or Miel, Nare or Negro and Cauca. There are also many smaller
streams flowing into the Magdalena from both sides of the valley. Of
those named, the Funza drains the "sabana" of Bogota and is celebrated
for the great fall of Tequendama, about 480 ft. in height; the
Sogamoso passes through some of the richest districts of the republic;
and the Cesar rises on the elevated slopes of the Sierra Nevada de
Santa Marta and flows southward across a low plain, in which are many
lakes, to join the Magdalena where it bends westward to meet the
Cauca. The course of the Magdalena traverses nine degrees of latitude
and is nearly 1000 m. long. It