38 SEATS AND SADDLES. 



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 gravity of the whole coincides with the centre 

 of motion of the vessel. This is what is called " trim," 

 as we all know ; and the yachtsman knows well the 

 effect of sending a man or two into the bows, when 

 running before the wind, and the use of keeping his 

 hands aft when in stays ; but he will be chary of alter- 

 ing the builder's trim, which makes these two centres 

 coincide mathematically ; he may never find it again, 

 as has happened in some remarkable instances. Now 

 the horse under a rider must have the trim that suits 

 the objects of the latter ; and for general purposes the 

 ship-builder's trim or the carter's trim will be found the 

 most advantageous. The bringing the rider's body, 

 from the hips upwards, slightly forwards or backwards, 

 will answer exactly the same purposes as the shifting 

 the hands in a yacht or the sacks in a cart. It can 

 answer no good purpose to alter the regular trim. To 

 persist in sailing a boat out of trim ends in a capsize, 

 or in carrying away spars at least ; just as riding out of 

 trim usually terminates in a " purl," and always in the 

 premature destruction of the horse's legs. 



And just as too heavy a bowsprit or jib-boom will 

 destroy the trim of a boat, the overhanging position of 

 the horse's head and neck destroys the animal's proper 

 trim after a rider is placed on its back; and the ques- 

 tion is, therefore, how this may be remedied, seeing 

 that we cannot shift a hea'd and neck like a jib-boom. 

 Fig. 3 shows three levers, d N, d 0, d P, of equal 



