COMMEKCE ON THE GeEAT K.IVER. 339 



CHAPTER XXy. 



The Navigation and Comraercial Resources of the Amazons. — Volume of 

 the Great River and its Tributaries. — Natural Wealth. — Sailing Craft and 

 Steamers. 



The Amazons is tlie most voluminous of rivers. Born 

 in Lake Lauricocha, among the Andes of Peru, the main 

 trunk runs northerly to the frontier of Ecuador, in a con- 

 tinuous series of rapids, and then easterly across the great 

 equatorial plain of the Continent, with an average current 

 of three miles an houi*. No other river runs in so deep a 

 channel to so great a distance. No other river can fur- 

 nish over 6000 miles of continuous navigation for large 

 vessels. For 2000 miles from its mouth the main stream 

 has not less than seven fathoms of water ; and not a fall 

 interrupts navigation for 2600 miles. The Pongo de Man- 

 seriche is the western limit to navigation. At Tabatinga 

 the width is a mile and a half, and the depth fi'om six to 

 twelve fathoms, according to season. In August and Sep- 

 tember a strong breeze sweeps up the lower part, so that 

 schooners often go from Para to Obidos in ten days, or 

 one third of the ordinary time. On the Solimoens the 

 trade -wind is felt occasionally in the dry season; and 

 dense fogs frequently occur there, especially at night. 

 High tide at Para rises twelve feet, and this is felt 500 

 miles up the river.* Besides this, the Amazons annually 

 rises forty feet above its lowest point, its ebb and flow (the 



* A singular phenomenon is obsert'ed at Manaos, a daily interruption to 

 the fall of the Negro between June and October, due, doubtless, to the coun- 

 teracting influence of the ocean-tide. 



