June 17.--A very severe frost, the ice a quarter of an inch thick. About a mile down the river, we saw a native burial-place or tomb, not more than a month old; the characters carved on the trees were quite fresh: the tomb had no semicircular seats, but in other respects was similar to those seen on our last journey. The country still continued perfectly level, the greater part extremely good and rich; back from the river it was occasionally marshy, with barren rocky scrubs; the timber large, and generally good: we could not see beyond a mile on the opposite side, but the country there appeared much the same. One of the men, who was some distance ahead of the horses, saw a large party of the natives, who fled at his approach, and swam the river; there were upwards of twenty men, besides women and children: the moment they were safely across, they brandished their waddies and spears in token of defiance: this was the first time any of the natives were seen armed, or in any way hostilely inclined. The river ran to the north-west by north over a bottom of rock and sand: in point of depth, it was amply sufficient for much larger boats than ours; but it was impossible always to avoid concealed dangers, over which the waters did not cause the slightest ripple. The large boat struck on a sharp rock, and with such violence as to stave her bottom; she was immediately unladen, and temporarily repaired without injury to the cargo. Although the river is extremely low, there is a very large body of water in it; the outer banks are nearly a quarter of a mile wide, and far out of the reach of flood, the marks of which were, to our extreme astonishment, observed nearly fifty feet high. We have not seen during these last two days any hill or other eminence; the country within our sight and observation being perfectly level.