ward being a compromise division by which Great Britain received
about 7336 sq. m. and Brazil about 5405. The definite boundary line
starts from Mt. Roraima and follows the water-parting east and south to
the source of the Ireng or Mahu river, which with the Takutu forms the
boundary as far south as 1 deg. N. to enclose the basin of the Essequibo
and its tributaries, thence it turns east and north of east along the
Serra Acaria to unite with the unsettled boundary line of Dutch Guiana
near the intersection of the 2nd parallel north with the 56th meridian.
Negotiations were initiated in 1905 for the definite location of the
boundary with Dutch Guiana. Running north-east and south-east to enclose
the sources of the Rio Paru, it unites with the French Guiana line at 2
deg. 10' N., 55 deg. W., and thence runs easterly along the
water-parting of the Serra Tumuc-Humac to the source of the Oyapok,
which river is the divisional line to the Atlantic coast. The boundary
with French Guiana (see GUIANA), which had long been a subject of
dispute, was settled by arbitration in 1900, the award being rendered by
the government of Switzerland. The area of the disputed territory was
about 34,750 sq. m.

_Physical Geography._--A relief map of Brazil shows two very irregular
divisions of surface: the great river basins, or plains, of the
Amazon-Tocantins and La Plata, which are practically connected by low
elevations in Bolivia, and a huge, shapeless mass of highlands filling
the eastern projection of the continent and extending southward to the
plains of Rio Grande do Sul and westward to the Bolivian frontier.
Besides these there are a narrow coastal plain, the low plains of Rio
Grande do Sul, and the Guiana highlands on the northern slope of the
Amazon basin below the Rio Negro.

Relief.

The coastal plain consists in great part of sandy beaches, detritus
formations, and partially submerged areas caused by uplifted beaches
and obstructed river channels. Mangrove swamps, lagoons and marshes,
with inland canals following the coast line for long distances, are
characteristic features of a large extent of the Brazilian coast.
Parts of this coastal plain, however, have an elevation of 100 to 200
ft., are rolling and fertile in character, and terminate on the coast
in a line of bluffs. In the larger depressions, like that of the
Reconcavo of Bahia, there are large alluvial areas celebrated for
the