THE AMAZON VALLEY. 
415 
of the river requires to be overcome, and thus delays the 
commencement of the flood, while it facilitates that of 
the ebb. This is^very remarkable in all the smaller 
rivers about Para. Taking this as our guide, we shall 
be able to ascertain which way the current in the Tagi- 
puru sets, independently of the tide. 
On my journey from Para to the Amazon, our canoe 
could only proceed with the tide, having to wait moored 
to the bank while it was against us, so that we were of 
course anxious to find the time of our tedious stoppages 
diminished. Up to a certain point, we always had to wait 
more time than we were moving, showing that the current 
set against us and towards Para ; but after passing that 
point, where there was a bend, and several streams met, 
we had but a short time to wait, and a long ebb in our 
favour, showing that the current was with us or towards 
the Amazon, whereas it would evidently have been dif- 
ferent had there been any permanent current flowing from 
the Amazon through the Tagipuru towards Para. 
I therefore look upon the Tagipuru as a channel 
formed by the small streams between the Tocantins and 
Xingu, meeting together about Melgago, and flowing 
through a low swampy country in two directions, towards 
the Amazon, and towards the Para river. 
At high tides the water becomes brackish, even up to 
the city of Para, and a few miles down is quite salt. 
The tide flows very rapidly past Para, up all the adja- 
cent streams, and as far as the middle of the Tagipuru 
channel ; another proof that a very small portion, if any, 
of the Amazon water is there to oppose it. 
The curious phenomenon of the bore, or “piroroco,” in 
