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INDIA

exit to the sea may be reckoned at 1 foot per mile, a
gradient which does not interfere with the navigation of
its lower reaches, and allows the river to slide in solemn
majesty to. its destination. The part which the Jumna
and the Ganges take as fertilising agents, enriching the
soil of thousands of acres of otherwise unproductive
country by means of the magnificent canal system to
which they give rise, will be dealt with elsewhere. In
the lower part of its basin the level flats of lower Bengal
are so freely watered by countless natural channels that
artificial irrigation becomes unnecessary.
The Brahmaputra, from its debouchment into the
plains of Assam to its junction with the Ganges, is very
similar in its general characteristics to the latter river,
although the districts which it drains in North-Eastern
Assam, and (through the agency of its great tributary, the
Megna) in Southern Assam, are widely distinct from the
flat alluvial plains which border the Ganges. The
Brahmaputra is a majestic river when it rolls in full
flood down the comparatively narrow valley of Assam.
The distance from bank to bank is often counted by
miles ; and the dense forest-clad slopes of the lower
Himalayas to the north, beyond the wide swampy grass
jungles of the Doars (the Terai of the eastern frontier),
through which flow the Teesta from Darjiling, and the
Monis from Bhutan, together form with the hills of the
Khasia and Garo plateaux on the south, an impressive
setting to its broad solemnity. Such effects are wanting
in the sandy flats about the Ganges. That the channels
of all the great rivers of the Gangetic plain are constantly
shifting and changing hardly needs assertion, but there is
no record of any general change of the bed of the entire
river, or of its displacement for scores of miles, such as is
apparent in the Indus. The Brahmaputra has no room
for any large changes of this nature; but in the lowlying
 delta lands of the combined rivers, channels shift
and change so often that it is probable that no general
map would define them correctly for more than a year
or two.