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ON THE INFLUENCE OF EXERCISE 
measure of speed and burthen we can impose upon a horse, so that 
his exercise or work do not inflict immediate ruin upon him, and 
that the saddle and the collar do not become to him at once insup- 
portable and destructible. 
In observing the influence of exercise on horses in this novel 
point of view, we find that all muscular action tends to produce 
efforts whose united powers constitute what in one word we de- 
nominate strength. 
It is not at all times that the efforts of the same horse are equi- 
valent in force ; his power will be commensurate, first, with the 
weight he has to carry; secondly, with the speed he has to go at; 
thirdly, with the duration of the pace; fourthly, with his breed; 
fifthly, with the season and the weather, and the state of the ground 
he goes upon. 
First, as to the amount of weight and speed. As attention has 
already been called to these points in another place (dans la Re- 
action Agricole , Nos. 78 and 79), permit me here, gentlemen, 
to recall your attention to the principal passages of that article. 
The exercise we impose on a horse ought, in general, to be so 
rated that his strength may counterbalance the exertions we re- 
quire of him. The weight to be carried, or the load to be drawn, 
it is that first calls forth the animal’s strength, and constitutes the 
labour he has to perform. Although in appearance he may possess 
greater strength for the saddle than for draft, that, in reality, is no 
hindrance to him to acquiring the power of drawing to a greater 
amount than he is able to carry. The burthen intended to be 
placed upon the back, however, ought to be estimated according to 
the animal’s natural strength , the same as science has established 
the rule in regard to man. 
As a mean, a man will support without exhaustion two-fifths of 
his own weight : i. e. the individual who weighs sixty-two kilo- 
grammes and a-half, will be able to carry easily a weight of twenty- 
five kilogrammes. Now, since a horse weighs about four times 
as much as a man, it follows that the former, weighing 250 kilo- 
grammes, should carry a weight of 100 kilogrammes. This cal- 
culation is taken as a mean, to serve us as a datum in estimating 
the proportion the burthen ought to bear to the physical strength of 
the animal, as well as to the rate of speed at which he is to go ; 
and, again, between horses of different ages, sexes, breeds, form, 
&c. 
We know very well that the mean we have fixed is capable of 
considerable augmentation, the same with men as with animals, 
who, once exercised at an early age and with judgment, acquire 
capabilities truly astounding. 
Man, in this particular, possesses advantages over the horse. 
