750 
IMPROVEMENT OF AGRICULTURAL HORSES, 
combined movement having the effect of advancing the body, 
and with it whatever objects may be attached, it follows 
naturally that when the weight of the animal is sufficient to 
overcome the resistance of the object to be moved, very little 
muscular force is necessary, but, assuming the weight to be 
insufficient, a proportionate increase in muscular action is 
required to produce the same result. The exhaustion w’hich 
follows this active exertion is detrimental to its continuance, 
while the almost passive employment of the weight of carcase 
in draught is attended with trifling expenditure of power. 
Great weight presupposes bulk, which is incompatible with 
speed, and hence animals remarkable for extraordinary powers 
of draught are inevitably slow. The injurious consequences 
arising from overtaxing the powers of the horse are quite well 
understood, and hence the desire for the cultivation of animals 
possessing a preponderance of the essential qualification. It 
must not, however, be forgotten that the error in the opposite 
extreme is not the less absurd, although harmless to the animal. 
The unnecessary expenditure of power, the slowwork on a farm, 
which could be rapidly cultivated by lighter animals, and the 
extra expense of purchasing and feeding the larger horses, 
are all arguments against a-system of arrangement which 
does not take into calculation the amount of/orce required 
in relation to the work to be done, admitting at the same 
time the general truth of the principle that power in excess 
is beyond all comparison to be preferred to power in de¬ 
ficiency. 
There is occasionally much difficulty in deciding upon the 
particular breed of horse best adapted for the agriculture of 
any large extent of country, owing to the great variety of 
its soils and surface-levels; and in the case of small farms, 
even a difficulty similar in kind, though less in degree, may 
sometimes be experienced. A light soil upon the oolites, a 
more tenacious soil of a mixed nature lower down, and an 
intractable soil upon unmitigated clay, may exist upon the 
holding, and -even be so impartially distributed that the 
farmer may be puzzled to decide which shouldjmost influence 
his choice of horses. The problem will generally be most 
satisfactorily solved by recollecting that, while the heavy 
horse can work the lighter land, the converse of the propo¬ 
sition bv no means obtains. 
In the West of England, as already shown, the principal 
soils requiring arable cultivation are upon the chalks, green¬ 
sand, oolite, and the Kimmeridge and lias clays. 
In localities where the lias forms a large part of the cul¬ 
tivated soil, none but powerful animals can be employed with 
