1 85 1.] INDIAN CARRIERS. 169
a height of two hundred and fifty feet, to which may be added fifty feet for the height of the station at which the observations were made at Barra, making three hundred feet. Now the height of Barra above the sea I cannot consider to be more than a hundred feet, for both my own observations and those of Mr. Spruce with the aneroid would make Barra lower than Para, if the difference of pressure of the atmosphere was solely owing to height, the barometer appearing to stand regularly higher at Barra than at Para, — a circumstance which shows the total inapplicability of that instrument to determine small heights at very great distances. I cannot therefore think that Sao Carlos is more than four hundred, or at the outside five hundred feet, above the level of the sea. Should, as I suspect, the mean pressure of the atmosphere in the interior and on the coasts of South America differ from other causes than the elevation, it will be a difficult point ever accurately to ascertain the levels of the interior of this great continent, for the distances are too vast and the forests too impenetrable to allow a line of levels to be carried across it.
When my Indians returned with the roots of timbo, we all set to work beating it on the rocks with hard pieces of wood, till we had reduced it to fibres. It was then placed in a small canoe, filled with water and clay, and well mixed and squeezed, till all the juice had come out of it. This being done, it was carried a little way up the stream, and gradually tilted in, and mixed with the water. It soon began to produce its effects : small fish jumped up out of the water, turned and twisted about on the surface, or even lay on their backs and sides. The Indians were in the stream with baskets, hooking out all that came in the way, and diving and swimming after any larger ones that appeared at all affected. In this way, we got in an hour or two a basketful of fish, mostly small ones, but contain- ing many curious species I had not before met with. Numbers escaped, as we had no weir across the stream ; and the next day several were found entangled at the sides, and already putrefying. I now had plenty to do. I selected about half a dozen of the most novel and interesting species to describe and figure, and gave the rest to be cleaned and put in the pot, to provide us a rather better supper than we had had for some days past.
The next morning early our porters appeared, consisting of
