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Random Facts about Rivers
SOME GREAT RIVERS.--From Haswell's little work for
engineers and mechanics the following figures are taken,
showing the lengths of the largest rivers on the various
continents:
EUROPE. Volga, Russia: 2,500 Danube:
1,800 Rhine: 840 Vistula: 700 ASIA. Yeneisy and Selenga:
3,580 Kiang: 3,290 Hoang Ho: 3,040 Amoor: 2,500 Euphrates:
1,900 Ganges: 1,850 Tigris: 1,160
AFRICA. Nile: 3,240 Niger: 2,400
Gambia: 1,000
SOUTH AMERICA. Amazon and Beni: 4,000
Platte: 2,700 Rio Madeira: 2,300 Rio Negro: 1,650 Orinoco:
1,600 Uruguay: 1,100 Magdalena: 900
NORTH AMERICA. Mississippi and
Missouri: 4,300 Mackenzie: 2,800 Rio Bravo: 2,300 Arkansas:
2,070 Red River: 1,520 Ohio and Alleghany: 1,480 St.
Lawrence: 1,450
The figures as to the length of the
Nile are estimated. The Amazon, with its tributaries
(including the Rio Negro and Madeira), drains an area of
2,330,000 square miles; the Mississippi and Missouri,
1,726,000 square miles; the Yeneisy (or Yenisei, as it is
often written) drains about 1,000,000 square miles; the
Volga, about 500,000.
In this group of great rivers the St.
Lawrence is the most remarkable. It constitutes by far the
largest body of fresh water in the world. Including the
lakes and streams, which it comprises in its widest
acceptation, the St. Lawrence covers about 73,000 square
miles; the aggregate, it is estimated, represents not less
than 9,000 solid miles--a mass of water which would have
taken upward of forty years to pour over Niagara at the
computed rate of 1,000,000 cubic feet in a second. As the
entire basin of this water system falls short of 300,000
square miles, the surface of the land is only three times
that of the water. Rivers hold in
suspension 100th of their volume (more or less) of mud, so
that if 36 cubic miles of water (the estimated quantity)
flow daily into the sea, 0.36 cubic miles of soil are daily
displaced.
The Rhine carries to the sea every day
145,980 cubic feet of mud.
The Po carries out the land 228 feet
per annum, consequently Adria which 2,500 years ago was on
the sea, is now over 20 miles from it.
The enormous amount of alluvium
deposited by the Mississippi is almost incalculable, and
constantly renders necessary extensive engineering
operations in order to remove the impediments to navigation.
The flight of wild ducks is estimated at 90 miles per
hour, that of the swift at 200 miles, carrier pigeons 38
miles, swallows 60 miles, migratory birds have crossed the
Mediterranean at a speed of 120 miles per hour.
The Nile has a fall of 6 ins. in 1,000
miles. The rise of the river commences in June, continuing
until the middle of August, attaining an elevation of from
24 to 26 feet, and flowing the valley of Egypt 12 miles
wide. In 1829 it rose to 26 cubits, by which 30,000 persons
were drowned. It is a terrible climate to live in, owing to
the festering heat and detestable exhalations from the mud,
etc., left on the retiring of the Nile, which adds about 4
inches to the soil in a century, and encroaches on the sea
16 feet every year. Bricks have been found at the depth of
60 feet, showing the vast antiquity of the country. In
productiveness of soil it is excelled by no other in the
world.
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