44 
Trunk Drainage. 
the direct distance is about 60 miles, but the river follows a 
tortuous course of 100 miles. From Northampton it proceeds 
north-east to Higham-Ferrars ; then, with many windings past 
Thrapstone and Oundle, it runs due north to Wanslord, and, 
turning east, passes on to Peterborough, bringing with it the 
waters of more than twenty brooks from the north-western slopes 
of Northamptonshire, though receiving scarcely any affluent on 
its Huntingdonshii'e side. At Peterborough it enters the Fens, 
across which it is now principally conducted by four artificial 
cuts, so that its original wandering channels are, in some cases, 
hardly traceable. With the exception of a bend at Guyhirn, and 
another at Wisbech, its course to sea is now nearly a straight 
line of 30 miles, entering the Wash through the last artificial cut, 
about 3 miles below Sutton Bridge. The area draining into 
the Nene above Peterborough is 408,640 acres, or about 638 
square miles, of which about 16,000 acres constitute the " upper 
valley," injured by floods. The Fens are burdened with the 
drainage of a tract of about six times their own area ; but this 
attenuated irregular fringe of low ground receives the down- 
flowing waters from a surface twenty-five times its size. It is 
true that this area is greater at the head than at points lower in 
the course of the stream, so that the common difficulty of having 
to provide for a largely-increasing area of drainage and flood- 
waters does not here occur. But then the sinuosity of the 
channel wastes a great deal of the fall which would give impulse 
to tlie outflow of the river : the straight distance between North- 
ampton and Peterborough is 36 miles, and, from the difference 
in elevation, there is an inclination of more than 5 feet per mile 
along this line ; but, the river flowing 60 miles in place of 36, 
the slope is diminished to about 3 feet per mile. And when, 
arrived at Peterborough, with still 30 miles to run before 
emptying into the sea, the river is at so low a level as to be 
only about 15 feet higher than low-water mark. Hence it neces- 
sarily moves onward with a sluggish pace, besides being stopped 
and driven back again by every tide. Spring tides of 20 feet 
rise, at the river mouth, to an elevation of 4 or 5 feet higher than 
the Nene surface at Peterborough — the water-line thus sloping 
inland instead of towards the sea — effectually blockading and 
driving back the stream between that point and the sea ; though, 
as the tide sinks again in the estuary Ijefore it has had time to 
penetrate so far inland, the tidal pulse is but little observed at 
Peterborough, and the surface of the river soon regains its trifling 
inclination towards its outfall. 
Below Peterborough the Nene formerly traversed the Great 
Level, swelling into broad meres and pools, and with its various 
channels uniting with the Ouse, discharging below Wisbech 
