634 General Notes. | September, 
GEOGRAPHY AND TRAVELS.'! 
THe Amazon.—The U. S. corvette Enterprise, Commander 
‘Thomas O. Selfridge, arrived off Para, Brazil, on the 24th of 
May, having been ordered to make a survey of the Amazon 
river as far as Manaos, and the Madeira as far as San Antonio. 
From a correspondent of the New York Herald we learn that the 
Enterprise started up the river on the 3d of June. Passing the 
mouth of the Tocantins she entered the first narrow canal. These 
natural canals or furos resemble the artificial channel made by 
Capt. Eads at the mouth of the Mississippi—the heavy growth 
of, aquatic plants and the thick interlacing of the roots of the 
trees forming in these narrow passages barriers similar to the 
mattresses used by him. A frigate may pass through these natu- 
ral jetties of the Amazon without fear, for the rush of water 
keeps the way clear. 
Two serious accidents to the machinery caused considerable 
delay, but the survey had been conducted successfully at the 
rate of about sixty miles a day up to the date of this letter, on 
June 15th, off Serpa, thirty miles below the mouth of the 
Madeira. No triangulation is undertaken, but simply a track 
chart is to be made. The points noted are the depths, the pro- 
file of the shore, the position of the islands, the courses steered, 
` the bearings of prominent points, the fixings of landmarks, the 
strength of the current, the character of the banks, the compass 
deviations, the meteorological changes, the barometric altitudes 
and the latitude and longitude of the towns, villages, bars, shoals 
and rocks of the river. Hees 
A correspondent of the New York World gives an interesting ` 
account of the Island of Marajo, the largest in South America, 
variety of valuable timber, medicinal plants and a great number 
of India rubber trees (Syphonia elastica). The prairie is devoted 
