he lower Castanho. The
lower main stream, and the lower portion of its main affluent, the
Castanho, had been commercial highways for rubbermen and settlers for
nearly two decades, and, as we speedily found, were as easy to
traverse as the upper stream, which we had just come down, was
difficult to traverse; but the governmental and scientific
authorities, native and foreign, remained in complete ignorance; and
the rubbermen themselves had not the slightest idea of the headwaters,
which were in country never hitherto traversed by civilized men.
Evidently the Castanho was, in length at least, substantially equal,
and probably superior, to the upper Aripuanan; it now seemed even more
likely that the Ananas was the headwaters of the main stream than of
the Cardozo.

For the first time this great river, the greatest affluent of the
Madiera, was to be put on the map; and the understanding of its real
position and real relationship, and the clearing up of the complex
problem of the sources of all these lower right-hand affluents of the
Madiera, was rendered possible by the seven weeks of hard and
dangerous labor we had spent in going down an absolutely unknown
river, through an absolutely unknown wilderness. At this stage of the
growth of world geography I esteemed it a great piece of good fortune
to be able to take part in such a feat--a feat which represented the
capping of the pyramid which during the previous seven years had been
built by the labor of the Brazilian Telegraphic Commission.

We had passed the period when there was a chance of peril, of
disaster, to the whole expedition. There might be risk ahead to
individuals, and some difficulties and annoyances for all of us; but
there was no longer the least likelihood of any disaster to the
expedition as a whole. We now no longer had to face continual anxiety,
the need of constant economy with food, the duty of labor with no end
in sight, and bitter uncertainty as to the future.

It was time to get out. The wearing work, under very unhealthy
conditions, was beginning to tell on every one. Half of the camaradas
had been down with fever and were much weakened; only a few of them
retained their original physical and moral strength. Cherrie and
Kermit had recovered; but both Kermit and Lyra still had bad sores on
their legs, from the bruises received in the water work. I was in
worse shape. The after effects of the fever still hung on; and the leg
which had been hurt wh