416 A JOURNEY IN BRAZIL. 
indisposition at Manaos for some days at the time we had 
appointed for the excursion, Major Coutinho preceded me, 
and had already made one trip to the serra, with some very 
interesting results, when I joined him, and we took a sec- 
ond journey together. Monte Alegre lies on a side arm of 
the Amazons, a little off from its main course. This side 
arm, called the Rio Gurupatuba, is simply a channel, run- 
ning parallel with the Amazons, and cutting through from 
a higher to a lower point. Its dimensions are, however, 
greatly exaggerated in all the maps thus far published, 
where it is usually made to appear as a considerable north- 
ern tributary of the Amazons. The town stands on an 
elevated terrace, separated from the main stream by the Rio 
Gurupatuba and by an extensive flat, consisting of numer- 
ous lakes divided from each other by low, alluvial land, and 
mostly connected by narrow channels. To the west of the 
town this terrace sinks abruptly to a wide sandy plain 
called the Campos, covered with a low forest-growth, and 
bordered on its farther limit by the picturesque serra of 
Erere*. The form of this mountain is so abrupt, its rise 
from the plains so bold and sudden, that it seems more 
than twice its real height. Judging by the eye and com- 
paring it with the mountains I had last seen, the Corco- 
vado, the Gavia, and Tijuca range in the neighborhood of 
Rio, - - 1 had supposed it to be three or four thousand feet 
high, and was greatly astonished when our barometric ob 
servations showed it to be somewhat less than nine hundred 
feet in its most elevated point. This, however, agrees with 
Martius's measurement of the Almeyrim hills, which he 
says are eight hundred feet in height. 
We passed three days in the investigation of the Serra 
of Erere*, and found it to consist wholly of the sandstone 
