Trunk Drainage. 
11 
manured soil, and the refuse of towns and villages — all present 
in the floods, and tending to enrich them. It is this process 
still going on, principally in the rainy season — tliough it may be 
very slightly perceptible from year to year — that gives to our 
meadows their luxuriance of coarse fotlder. Smaller streams 
often contain also the manurial refuse of towns which are near 
them : as, for instance, the Tliame, a tributary of the Trent, 
which carries in its waters the whole sewerage of Birmingham, 
and occasionally deposits these, with fertilising effect, upon the 
fine meadows of Drayton-Manor. But, productive as the soil 
of our meadows may be, it is only in favourable years that the 
grass attains to much bulk or value. The farmers in the Trent 
valley, by the Ouse, Nene, Thames, or Severn, in the rainiest 
as well as the drier counties, are pretty well agreed in declaring, 
that while the small winter floods compensate for any damage they 
may do ly the cheap manure they leave behind, the great Jioods of 
wet seasons inflict very heavy injury by hanging upon the land. 
The mere stagnation of water upon the surface, or within the 
subsoil, is condemned by all our principles of drainage and 
irrigation, and our theories of vegetable life ; but the submer- 
gence of pastures and meadows under temporary lakes of several 
feet depth — into which most of our river valleys are so fre- 
quently converted — places pasture grasses, for many days to- 
gether, in a position where only pond- weed and the aquatic 
plants, among which frogs and reptiles hide, can grow or live ;. 
and the perishing of useful vegetation, thus buried from the 
atmosphere, must be rapid and irrecoverable. Owing to exces- 
sive winter floods tlie grazier loses a half-year's keep for animals 
which he is compelled to crowd upon his upland pastures, or set 
upon artificial winter food before the severity of season needs it. 
He loses the power of grazing the meadows when they are 
most needed ; though in early spring, when the turnips are all con- 
sumed and before the upland pastures and young clovers are 
grown, they are, in dry years, the best pastures for sheep, and 
keep them for two or three weeks when food is most scarce, and, 
consequently, most valuable. His liay-cro-p becomes miserably 
deficient, and the aftermath scanty, coarse, and brown. The 
proportionate numbers of ordinarily and of hurtfully flooding 
winters are different upon different rivers ; but all our chief 
riverain grass-lands are subject to such utter deterioration at 
times, whilst most of them suffer every two or three years, and 
some very extensive meadows every year. 
2. Injury from Summer Flooding. 
Districts lying exposed to summer floods, in addition to those 
during the autumn and winter months of downfall, experience 
