igable. These rivers have been of great
service in the agricultural development of this part of Chile,
affording means of transportation where railways and highways were
entirely lacking. Some of the larger tributaries of these rivers,
whose economic value has been equally great, are the Mapocho, which
flows through Santiago and enters the Maipo from the north; the
turbulent Cachapoal, which joins the Rapel from the north; the Claro,
which waters an extensive part of the province of Talca and enters the
Maule from the north; the Nuble, which rises in the higher Andes north
of the peaks of Chillan and flows entirely across the province of
Nuble to join the Itata on its western frontier; the Laja, which rises
in a lake of the same name near the Argentine frontier in about lat.
35 deg. 30' S. and flows almost due west to the Bio-Bio; and the Cautin,
which rises in the north-east corner of Cautin and after a tortuous
course westward nearly across that province forms the principal
confluent of the Imperial. The unsettled southern regions of Chiloe
(mainland) and Magallanes are traversed by a number of important
rivers which have been only partially explored. They have their
sources in the Andes, some of them on the eastern side of the line of
highest summits. The Puelo has its origin in a lake of the same name
in Argentine territory, and flows north-west through the Cordilleras
into an estuary (Reloncavi Inlet) of the Gulf of Reloncavi at the
northern end of the Gulf of Chacao. Its lower course is impeded in
such a manner as to form three small lakes, called Superior, Inferior
and Taguatagua. A large northern tributary of the Puelo, the Manso,
has its sources in Lake Mascardi and other lakes and streams
south-east of the Cerro Tronador, also in Argentina, and flows
south-west through the Cordilleras to unite with the Puelo a few miles
west of the 72nd meridian. The Reloncavi Inlet also receives the
outflow of Lake Todos los Santos through a short tortuous stream
called the Petrohue. The Comau Inlet and river form the boundary line
between the provinces of Llanquihue and Chiloe, and traverse a densely
wooded country in a north-westerly direction from the Andes to the
north-eastern shore of the Gulf of Chacao. Continuing southward, the
Yelcho is the next important river to traverse this region. It drains
a large area of Argentine territory, where it is called