' UNFORESEEN EFFECTS OF DRAINING. 
365 
So far as respects the immediate improvement of soil and 
climate, and tlie increased abundance of the harvests, the Eng- 
lisli system of surface and subsoil drainage has fully justified 
the eulogiums of its advocates; but its extensive adoption 
appears to have been attended with some altogether unforeseen 
and undesirable consequences, very analogous to those which 
I have described as resulting from the clearing of the forests. 
The under-drains carry off very rapidly the water imbibed by 
the soil from precipitation, and through infiltration from neigh¬ 
boring springs or other sources of supply. Consequently, in 
wet seasons, or after heavy rains, a river bordered by artifi¬ 
cially drained lands receives in a few hours, from superficial 
and from subterranean conduits, an accession of water which, 
in the natural state of the earth, would have reached it only 
by small instalments after percolating through hidden paths 
for weeks or even months, and would have furnished perennial 
and comparatively regular contributions, instead of swelling 
deluges, to its channel. Thus, when human impatience rashly 
substitutes swiftly acting artificial contrivances for the slow 
methods by which nature drains the surface and superficial 
strata of a river basin, the original equilibrium is disturbed, 
the waters of the heavens are no longer stored up in the earth 
to be gradually given out again, but are hurried out of man’s 
domain with wasteful haste ; and while the inundations of the 
river are sudden and disastrous, its current, when the drains 
have run dry, is reduced to a rivulet, it ceases to supply the 
power to drive the machinery for which it was once amply 
sufficient, and scarcely even waters the herds that pasture upon 
its margin.* 
Irrigation and its Climatic and Geographical Effects. 
We know little of the history of the extinct civilizations 
which preceded the culture of the classic ages, and no nation 
has, in modern times, spontaneously emerged from barbarism, 
* Babinet condemns even the general draining of marshes. “ Drain¬ 
ing,” says he, “has been much in fashion for some years. It has been a 
special object to dry and fertilize marshy grounds. My opinion has always 
