e west bank 9 kilometres
below Fort Coimbra, thence inland 4 kilometres to a point in lat. 19
deg. 45' 36" S. and long. 58 deg. 04' 12.7" W., whence it follows an
irregular course N. and E. of N. to Lakes Mandiore, Gaiba or Gahiba, and
Uberaba, then up the San Matias river and N. along the Sierra Ricardo
Franco to the headwaters of the Rio Verde, a tributary of the Guapore.
This part of the boundary was turned inland from the Paraguay to
include, within Brazilian jurisdiction, Fort Coimbra, Corumba and other
settlements on the west bank, and was modified in 1903 by the recession
of about 1158 sq. m. to Bolivia to provide better commercial facilities
on the Paraguay. The line follows the Verde, Guapore, Mamore and Madeira
rivers down to the mouth of the Abuna, in about lat. 9 deg. 44' S., as
determined by the treaty of 1903. This is a part of the original
colonial frontier, which extended down the Madeira to a point midway
between the Beni and the Amazon, and then ran due W. to the Javary. The
treaty of 1867 changed this starting-point to the mouth of the Beni, in
lat. 10 deg. 20' S., and designated a straight line to the source of the
Javary as the frontier, which gave to Brazil a large area of territory;
but when the valuable rubber forests of the upper Purus became known the
Brazilians invaded them and demanded another modification of the
boundary line. This was finally settled in 1903 by the treaty of
Petropolis, which provided that the line should ascend the Abuna river
to lat. 10 deg. 20' S., thence along that parallel W. to the Rapirran
river which is followed to its principal source, thence due W. to the
Ituxy river which is followed W. to its source, thence to the source of
Bahia Creek which is followed to the Acre or Aquiry river, thence up the
latter to its source, whence if east of the 69th meridian it runs direct
to the 11th parallel which will form the boundary line to the Peruvian
frontier. This frontier gave about 60,000 sq. m. of territory to Brazil,
for which the latter gave an indemnity of L2,000,000 and about 1158 sq.
m. of territory on the Matto Grosso frontier. The boundary with Paraguay
is unsettled, but an unratified treaty of the 23rd of November 1894
provides that the line shall start from a point on the Paraguay river 3
m. north of Fort Olimpo and run south-west in a straight line to an
intersection with the Pilcomayo in long. 61 deg. 28' W., where it unites
with the Argentine boundary. The bound