50 
The Mechanical \Condition of the Soil 
considered that we run a groat risk of getting tlie soil pasty 
or muddy wlicn rain falls upon it ; and, unless under the circum- 
stances named, it is better to keep the soil in a state of small 
lumps rather than reduce them into a dusty condition. The 
same care is necessary in preparing it for the seed-wheat. The last 
ploughing should leave the land in ridges, and the ploughed earth 
should not be broken down or crushed until the time of sowing. 
An early preparation of these soils is advisable, so that the 
work may be accomplished whilst the soil can be thrown together 
in a dry state, after which it may remain untouched until the 
seed-time. Narrow lands will generally be found best for soils 
of this class, so that, in carrying out the sowing, the drill and 
harrows may cover the width between the two furrows, and the 
horses walk in the furrows, so as not to trample the land. If 
a fallow has been well managed, so that the land has been 
thoroughly cleaned from weeds, in case of a wet seed-time, I 
should have no hesitation in sowing the land broadcast, rather 
than wait to drill the seed with the risk of injuring the condition 
of the land and the certainty of delaying the time of sowing. 
Clays of this strong character are exceedingly sensitive of 
moisture. They rapidly absorb it from the air, and when the 
rain falls, the interstices in the surface soon become closed so as 
to obstruct its passage. If, whilst the soil is in this soft state, it 
be pressed, a firm adhesion of the particles takes place. The 
cups thus formed in the soil by the horses' feet continue to hold 
water long after the other ground has become dry. The clay 
soil, which expanded when it absorbed water, is disposed to 
contract again as it dries, whilst the adhesion formed by pressure 
still remains. If this adhesion is objectionable to tlie growth of 
the seed, as I shall show it to be, it ought to be avoided ; and for 
this reason the sowing of such land should be carried out as early 
as the climate of the district will permit, and the greatest care 
should be taken to avoid the injurious influence of treading the 
soil or pressing it by the use of implements, which may cause its 
adhesion. Few can at present estimate the full amount of 
injury occasioned on these soils by the treading of horses on 
their work, — an injury Avhich probably will only be rightly 
estimated when we supersede this portion of their labour by 
steam-cultivation. 
After the seed is sown, the harrowing must only be carried out 
so far as to cover the seed, for the reduction of the surface to a 
fine tilth is very objectionable ; rolling should certainly be 
avoided. The injurious effect of a fine surface arises from its 
disposition, in case of violent rain, to form a muddy coating, 
which, when dry, acts as a crust upon the surface. This cover- 
ing interrupts the free entrance of the atmospheric air into the 
