THE INDIAN PENINSULA 135

maputra, and which is not far removed from the source
of the largest affluent (sometimes reckoned as the main
stream) of the Ganges. Enclosed between the Indus and
the Sutlej, the three other great rivers of the Punjab, the
Jehlam (Jehlum), the Chenab, and the Ravi rise; the head
of the Jehlam (which is largely increased in volume by
the Sind and Kishenganga affluents) lies in the heart of
Kashmir, and the Chenab and Ravi take their rise from
contiguous sources east of the little Rajput state of Chamba.
All these rivers have one feature in common. They all
lead off in a north-westerly direction before shaping their
course to the south-west to sweep through the plains of
the Punjab. We are so apt to regard the Indus as a
gigantic waterway passing south-west through the alluvial
flats of the Punjab and the sands of Sind, that we constantly
 overlook the fact that at least one-third of its
course of over 1500 miles is towards the north-west.
All the Punjab rivers derive their main water-supply
from the snows and mountain torrents of the Himalayas,
and all are liable to their periodic seasons of flood when
the snows melt off the higher ranges during the late
summer, and the monsoon at the same time brings up its
warm vapour-bearing currents to burst against the cool
summits of the peaks overlooking their sources. Then
(about July and August) comes the rush of life-giving
water to the steaming plains ; then is the anxious time
for the engineer and bridge-maker ; then the swelling
brown torrent spreads across miles of river bed, curling
and eddying with resistless sweep against piers - and
abutments, licking the neck of the bridge supports, and
bringing down heavy batteries of floating timber and uprooted
 trees. The flood action of all these Punjab rivers
is the same. There are no restraining natural revetments
to keep the river within bounds, nothing set by Nature to
prevent its carving out a fresh channel for itself in the
soft alluvial soil, and forsaking its old waterway and discarding
 its bridges (if they prove obstructive), taking up
an entirely new position. And this would happen yearly
but for the artificial constructions which are engineered