DRAINING OF SWAMPS. 437 
But there is probably no country where greater improve- 
ments of this sort have either been lately effected, or are now 
in course of accomplishment, than in our own. Not to speak 
of well-known works on the New Jersey seacoast and the 
shores of Lake Michigan, the people of the new State of Cali- 
fornia are engaging in this mode of subduing nature with as 
much enterprise and energy as they have shown in the search 
for gold. The Report of the Agricultural Department of the 
United States for January, 1872, notices, with more or less 
detail, several highly successful experiments in California in 
the way of swamp-drainage and securing land from overflow, 
and it appears that not far from 200,000 acres have either very 
recently undergone or will soon be subjected to this method of 
improvement. 
Agricultural Draining. 
I have commenced this chapter with a description of the 
dikes and other hydraulic works of the Netherland engineers, 
because both the immediate and the remote results of such 
operations are more obvious and more easily measured, though 
certainly not more important, than those of much older and 
more widely diffused modes of resisting or directing the flow 
of waters, which have been practised from remote antiquity in 
the interior of all civilized countries. Draining and irrigation 
are habitually regarded as purely agricultural processes, having 
little or no relation to technical geography; but we shall find 
that they exert a powerful influence on soil, climate, and animal 
and vegetable life, and may, therefore, justly claim to be re- 
garded as geographical elements. 
Superficial draining is a necessity in all lands newly re- 
claimed from the forest. The face of the ground in the woods 
is never so regularly inclined as to permit water to flow freely 
lately been constructed in England for draining these marshes. This discharge 
is equal to an area of 640 acres, or a mile square, with nearly three feet of 
water, 
