an raid; for they were absolutely unprepared to have any one come
from the unknown regions up-stream. They returned and were most
hospitable and communicative; and we spent the night there. Said
Antonio Correa to Kermit: "It seems like a dream to be in a house
again, and hear the voices of men and women, instead of being among
those mountains and rapids." The river was known to them as the
Castanho, and was the main affluent or rather the left or western
branch, of the Aripuanan; the Castanho is a name used by the rubber-
gatherers only; it is unknown to the geographers. We were, according
to our informants, about fifteen days' journey from the confluence of
the two rivers; but there were many rubbermen along the banks, some of
whom had become permanent settlers. We had come over three hundred
kilometres, in forty-eight days, over absolutely unknown ground; we
had seen no human being, although we had twice heard Indians. Six
weeks had been spent in steadily slogging our way down through the
interminable series of rapids. It was astonishing before, when we were
on a river of about the size of the upper Rhine or Elbe, to realize
that no geographer had any idea of its existence. But, after all, no
civilized man of any grade had ever been on it. Here, however, was a
river with people dwelling along the banks, some of whom had lived in
the neighborhood for eight or ten years; and yet on no standard map
was there a hint of the river's existence. We were putting on the map
a river, running through between five and six degrees of latitude--of
between seven and eight if, as should properly be done, the lower
Aripuanan is included as part of it--of which no geographer, in any
map published in Europe, or the United States, or Brazil had even
admitted the possibility of the existence; for the place actually
occupied by it was filled, on the maps, by other--imaginary--streams,
or by mountain ranges. Before we started, the Amazonas Boundary
Commission had come up the lower Aripuanan and then the eastern
branch, or upper Aripuanan, to 8 degrees 48 minutes, following the
course which for a couple of decades had been followed by the
rubbermen, but not going as high. An employee, either of this
commission or of one of the big rubbermen, had been up the Castanho,
which is easy of ascent in its lower course, to about the same
latitude, not going nearly as high as the rubbermen had gone; this we
found out while we ourselves were descending t