291 
STRENGTH OF THE CURRENT. 
We slept in tlie open air, on the left bank of the river, 
below the island ot Tomo. The night was beautiful and 
serene, but the torment of the mosquitos was so great near 
the ground, that I could not succeed in levelling the artificial 
horizon ; consequently I lost the opportunity of making an 
observation. 
On the 18th we set out at three in the morning, to be 
more sure of arriving before the close of the day at the 
cataract known by the name of the Tiaudal de los Guahibos- 
We stopped at the mouth of the Rio Tomo. The Indians 
went on shore, to prepare their food, and take some repose- 
When we reached the foot of the raudal, it was near five in 
the afternoon. It was extremely difficult to go up the cur- 
rent against a mass of water, precipitated from a bank ot 
gneiss several feet high. An Indian threw himself into the 
water, to reach, by swimming, the rock that divides the 
cataract into two parts. A rope was fastened to the point 
of this rock, and when the canoe was hauled near enough, 
our instruments, our dry plants, and the provision we had 
collected at Atures, were landed in the raudal itself. 
remarked wdth surprise, that the natural dam over which the 
river is precipitated, presents a dry space of considerable 
extent ; where we stopped to see the boat go up. 
The rock of gneiss exhibits circular holes, the largest ot 
which are four feet deep, and eighteen inches wide. These 
funnels contain quartz pebbles, and appear to have been 
formed by the friction of masses rolled along by the impulse 
of the waters. . Our situation, in the midst of the cataract, 
was singular enough, but unattended by the smallest danger- 
The missionary, who accompanied us, had his fever-fit <? n 
him. In order to quench the thirst by which he was tor- 
mented, the idea suggested itself to us of preparing a re- 
freshing beverage for him in one of the excavations of tee 
rock. We had taken on board at Atures an Indian basket 
called a mapire, filled with sugar, limes, and those gremdiV#*' 
or fruits of the passion-flower, to which the Spaniards g 1 ' ’’ 
the name of parclias. As we were absolutely destitute 0 
large vessels for holding and mixing liquids, we poured the 
water of the river, by means of a calabash, nto one of t‘ ie 
holes of the rock : to this we added sugar and lime-juic?_ 
In a few minutes we bad an excellent beverage, which 1 
