Atlantic (33 deg.45'
S. lat.), the boundary line between Brazil and Uruguay passes up that
rivulet and across to the most southerly tributary of Lake Mirim, thence
down the western shore of that lake to the Jaguarao and up that river to
its most southerly source. The line then crosses to the hill-range
called Cuchilla de Sant' Anna, which is followed in a north-west
direction to the source of the Cuareim, or Quarahy, this river becoming
the boundary down to the Uruguay. This line was fixed by the treaty of
1851, by which the control of Lake Mirim remains with Brazil. Beginning
at the mouth of the Quarahy, the boundary line between Brazil and
Argentina ascends the Uruguay, crosses to the source of the Santo
Antonio, and descends that small stream and the Iguassu to the Parana,
where it terminates. This line was defined by the treaty of 1857, and by
the decision of President Cleveland in 1895 with regard to the small
section between the Uruguay and Iguassu rivers. The boundary with
Paraguay was definitely settled in 1872. It ascends the Parana to the
great falls of Guayra, or Sete Quedas, and thence westward along the
water-parting of the Sierra de Maracayu to the _cerro_ of that name,
thence northerly along the Sierra d'Amambay to the source of the
Estrella, a small tributary of the Apa, and thence down those two
streams to the Paraguay. From this point the line ascends the Paraguay
to the mouth of the Rio Negro, the outlet of the Bahia Negra, where the
Bolivian boundary begins. As regards the Peruvian boundary, an agreement
was reached in 1904 to submit the dispute to the arbitration of the
president of Argentina in case further efforts to reach an amicable
settlement failed. The provisional line, representing the Brazilian
claim, begins at the termination of the Bolivian section (the
intersection of the 11th parallel with the meridian of 72 deg. 26' W.
approx.) and follows a semicircular direction north-west and north to
the source of the Javary (or Yavary), to include the basins of the Purus
and Jurua within Brazilian jurisdiction. The line follows the Javary to
its junction with the Amazon, and runs thence north by east direct to
the mouth of the Apaporis, a tributary of the Yapura, in about 1 deg.
30' S. lat., 69 deg. 20' W. long., where the Peruvian section ends. The
whole of this line, however, was subject to future adjustments, Peru
claiming all that part of the Amazon valley extending eastward to the
Madeira and