which a rubber-man had reached and claimed as his own. An hour farther down we came on a newly built house in a little planted clearing; and we cheered heartily.

From a photograph by Cherrie.

Castanha-tree. (Brazil-nut.)

No one was at home, but the house, of palm thatch, was clean and cool. A couple of dogs were on watch, and the belongings showed that a man, a woman, and a child lived there, and had only just left. Another hour brought us to a similar house where dwelt an old black man, who showed the innate courtesy of the Brazilian peasant. We came on these rubber-men and their houses in about latitude 10° 24'.

In mid-afternoon we stopped at another clean, cool, picturesque house of palm thatch. The inhabitants all fled at our approach, fearing an Indian raid; for they were absolutely unprepared to have any one come from the unknown regions upstream. 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 Castanha, and was the main affluent, or rather the left or western branch, of the Aripuanan; the Castanha 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 rubber-men 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 be

tween 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-imaginarystreams, 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° 48', following the course which for a couple of decades had been followed by the rubber-men, but not going as high. The lower main stream, and the lower portion of its main affluent the Castanha, had been commercial highways for rubber-men and settlers for nearly two decades; but the governmental and scientific authorities, native and foreign, remained in complete ignorance; and the rubber-men themselves had not the slightest idea of the headwaters, which were in country never hitherto traversed by civilized men. Evidently the Castanha 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 Madeira, 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 Madeira, 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

Pacova-tree.

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 while working in the rapids with the sunken canoe had taken a turn for the bad and developed an abscess. The good doctor, to whose unwearied care and kindness I owe much, had cut it open and inserted a drainage tube; an added