THE FRAMEWORK OP THE HORSE. 37 



at low degrees of speed, and attains his object as above 

 described; but for general riding it is of great importance 

 for the cavalry, indispensable to be able to turn in 

 sharp curves at higher degrees of speed. 



Instead of instituting a mathematical and physical 

 inquiry into the advantages of making the centres of 

 gravity and motion coincide, let us take from e very-day 

 life one or two instances that illustrate the principle 

 very satisfactorily. In a common two-wheeled cart the 

 whole body of the machine turns round on the axle, 

 and the centre of motion lies in a perpendicular falling 

 through the mid-point of this. A carter that under- 

 stands his business always adjusts the load in such a 

 manner that it neither presses too much on the horse's 

 back by lying too far forward, nor on his neck by being 

 too far back in the cart in fact he makes the centres of 

 motion and gravity to correspond as nearly as possible, 

 knowing from experience that his horse draws the cart 

 with greater ease, and can tarn, corners, &c., more readily, 

 when the load is thus adjusted, than in any other 

 manner. For special purposes, as going up hill, he shifts 

 the weight forward, but he is cautious in turning the 

 horse when the load is on the back : there is always 

 danger of falling. Sometimes, when his object is to 

 turn the cart round sharply on its own ground, he shifts 

 the weight to the rear, the horse having then perfect 

 liberty to circle round in the required direction ; but 

 he never adopts this for a journey, be it ever so short. 



Again, in a ship or boat of any kind, people that have 

 experienced sea- sickness soon find out where the centre 

 of motion lies, and nestle round it ; and the master who 

 sails her knows well that his cargo or load, whatever it 

 may be, must be so stowed away that the centre of 



