196 
ARE SOILS ENRICHED, IMPOVERISHED, [Part III. 
dicious, down-hill waggon-way, across fields, will 
sometimes act as a channel, and, catching soil 
laterally, convey it away from its proper owner. 
If your neighbour’s land lies below you on a 
steep hill-side, unless you wish to make him a 
present of your soil, pound it back on to your 
own land by a fence, and, when it accumulates 
against your own fence, cart it up the hill again. 
The beautiful terracing of the hill-side, whieh 
we see in southern mountain cultivation, origi¬ 
nates in the necessity of catching the stream of 
soil from above, and preventing its farther de¬ 
scent to the valley below, down which it would 
be washed, whether it were a dry valley or a 
river valley. 
In unusually heavy rains numbers of these 
terrace walls give way; and when a terrace goes 
which is high up the hill-side, a sort of earthen 
avalanche takes place, bearing crops, soil, and 
stone walls in succession to the vale below. 
In these works man shows himself as a strong 
• conservative . In alluding to man as a leveller , 
our great geologist admirably remarks: “ By 
ploughing up thousands of square miles, and ex¬ 
posing a surface for part of the year to the ac¬ 
tion of the elements, we assist the abrading force 
of rain, and diminish the conservative effects of 
