257 
4. The litter with the stumps and projecting roots and trunks 
of trees prevent the water from rapidly running over (he ground 
and from gaining the momentum and force which is necessary in 
order to erode and gully the soil. 
If the forest floor is not disturbed by fire, nor the litter trampled 
and compacted by cattle, it always reduces rapid surface drainage 
and largely, if not entirely, prevents erosive action. 
Recovery of washed soils. 
Just as deforestation of hillsides and hilltops is the first cause 
for inducing erosive action, so is reforestation the most effective 
means in curing the evil. This has been demonstrated in France, 
where the Government and the farmers together have spent, dur- 
ing the last thirty years, over ^40,000,000 and expect to expend 
three or four times that amount to reforest 1,000,000 acres of 
denuded mountain sides, the soil and debris from which has been 
carried by the. torrents of water into the plain, covering over 
8,000,000 acres of fertile ground and making it useless for agricul- 
ture. Sodding for pasture has been found mostly less effective 
and on the steeper slopes entirely ineffective. 
Whenever the ground in the hill country is not fit for agricultural 
use it should be set and kept in forest, not only to make it produce 
a timber crop, but also to prevent the erosion which finally becomes 
dangerous to ’the lower valley lands. Wherever agriculture is pos- 
sible and profitable there should be such a distribution of forest, 
pasture, and field as will secure the greatest immunity from erosive 
and torrential action of the waters. The forest should occupy all 
hilltops which, as a rule, have too thin a soil to allow profitable 
agricultural use; it should be kept growing on the steeper slopes 
where the water acquires the greatest momentum and the loosening 
of the soil by the plough furnishes a most favourable condition for 
erosive action ; it should be placed on all rocky, uneven, agricul- 
turally useless spots, because it will produce useful material even on 
such unfavourable situations, and, finally, forest belts should be 
maintained on long slopes alternately with fields and pastures, run- 
ning along the brow of the slope of widths and at distances pro- 
portionate to the character of the land and the angle of the slope 
on the steeper slopes closer together, on the gentler slopes further 
apart. These belts, acting as a barrier to break the force of the 
water, will prevent an undue accumulation of surface waters and 
will protect to a considerable degree the lower field from washing. 
Farmers, therefore, living in the eroded hill country should start 
upon the work of reforestation with a well conceived plan. They 
should determine beforehand which parts ought to be in forest, and 
which they may reasonably expect to adapt again to agricultural 
uses. They should understand that they must begin this work at 
the origin of the evil, at the very tops of the hills where the water 
begins to gather and acquire its force, and gradually proceed with 
their work down to the lower levels. 
<V 7 
