Practical Agriculture. 
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eastern, and northern provinces, aggregating into considerable 
estuaries round the coast line — such as the Eden, Lune, Ribble, 
Mersey, Dee, Conway, Towy, Taff, Usk, Avon, Parrett, Taw, 
Tainar, Dart, Exe, Test, Aran, Rother, Stour, Medway, Crouch, 
Blackwater, Colne, Orwell, Yar, Tees, Wear, Tyne and Tweed. 
Now, although outfall improvements yet remain to be effected, 
the principal outlets may be considered able to evacuate any 
amount of water likely to flow to them, because in most instances 
the drainage exigencies of the alluvial deltas, added to the 
demands of deep-water navigation, have caused them to be opened, 
embanked, and watchfully preserved. Thus, the great works 
which have procured an unimpeded outflow for the Ouse, Nene, 
Welland and Witham rivers, through the muddy shoals of the 
Wash, are justly celebrated as triumphs of engineering. Similar 
improvements of the Trent, Yorkshire Ouse, and associated 
streams, have facilitated the confluence of their waters with the 
Humber. In East Norfolk, not only the mouths of the streams 
have been guarded, but the very existence of the seaport of Yar- 
mouth has been secured by artificial ramparts of sand and beach. 
Below Chester the river Dee has been straightened, and a large 
tract of its white sands reclaimed. In Somersetshire the flat land 
has been embanked from the sea, and the mouth of the Parret 
and its connected rivers confined from spreading into shallow 
water ; while several harbours and estuaries along the south 
coast have skilfully contended with the waves and shifting 
shingle of the Channel. It is not so mrch the river mouths or 
the inland courses which are defective as drains for conveying 
away the surplus water from land. The main streams, branches, 
hecks, and brooks have neither been left to follow their natural 
levels, nor have their currents been directed by art ; but they have 
been dammed into reservoirs, intercepted for canals, held back as 
feeders for deep-water navigation, or lifted to gain a water- 
power for myriads of mills, especially in the northern, western, 
and central counties. Hence, in most of the low-lying districts 
of England, the broad meadows, coarse pasture, and wet arable 
lands fringing the rivers, are permanently damaged by the pre- 
vention of good husbandry and periodically visited with grievous 
losses and inundation ; while frequent disasters, with great 
destruction of property and even of human life, fall upon upland 
valleys. Over vast breadths of the country, too, where main 
drainage is not under systematic supervision as a first necessity 
for agriculture, water-courses are commonly found wandering in 
irregular channels, impeded in their flow, and too often choked 
with a semi-aquatic, semi-sylvan growth of vegetation. Improve- 
ments in the arterial drainage of England have been prevalent 
ol late years, but, in spite of legislation on this subject, the 
