On Dra,inin(j. 
410 
ample. Water will flow in larjre rivers with a fail of inches in 
a mile, so that one yard in 220 is a fall 9G times greater than 
what water will flow at, which must be sufficient to allow lor the 
friction of under-drains. I have stated the difficulty of water in 
heavy rains running from high-ridged lands and hills (holding clay 
in suspension) into the furrows and flat parts, filtering through 
the deposit of mud on the surface. Attention should be directed 
to prevent as much as possible the water running over the surface, 
to effect which the land should lie comparatively level between 
the drains, little or no more rise between the furrows than is pro- 
duced by setting the ridge and ploughing to it. 
As before stated, the furrows (except where the lands are of a 
proper width) are not to be taken as the course of the drains ; 
and if they are high-ridged lands, the levelling of them, so 
necessary to perfect drainage, must be considered. I am aware 
of the objections to levelling clay-soils urged by many, that the 
land will not drain so well, that the ridges of the lands by the 
surface-soil being removed will produce but little corn, and the 
heavy expense, if the spade and plough are combined so as to 
spread the surface-soil regularly over the land. To the first ob- 
jection, my experience proves that level land will drain better 
than high-ridged land, as the water has less tendency in heavy 
rains to flow over the surface, consequently there is less deposit 
of mud in the furrows and flat parts of the land, to prevent the 
infiltration of the water. To the second objection, the subsoil 
(iiot the nurf ace-soil^ should be made use of to level with, for it 
is most desirable to have the surface of the land when level of a 
uniform character, which it will not be if the surface-soil is made 
use of for levelling, as is the case if the plough only is used. 
Whatever mode may be adopted, the principle should be not to 
make use of the surface-soil, but so much of the subsoil as is 
necessary. The season best adapted for levelling and draining 
land, regard being had to the employment of the labourers, is 
from October to May ; and the mode which I recommend, where 
the lands do not rise more than from 7 to 12 inches, as shown in 
Fig. f), is to plough two rounds on each ridge, and the same or 
three in the old furrows, to open them as wide as possible ; with 
the spade dig the subsoil out of the ridges, and throw into the 
furrows, and proceed as shown by the plans, until by cross- 
ploughing the object intended is effected. Although on this plan 
there will be to some extent an admixture of surface and subsoil, 
and a larger quantity of manure will for once be necessary, the 
whole will be of a uniform character and deeper tilth — whereas, if 
the plough only is used on most lands, by baring the ridges of 
the surface-soil the injury is venj great. The cost of this mode 
of levelling land for spade-labour will be from 12.?. to 18.y. per 
