I9 6 THE SEAT. 



saddle. As the ribs of a horse swell out behind the girths, 

 the rider who gets well down into the saddle will sit forward 

 in it. We may often hear people say that a man ought to sit 

 well back when going over fences ; but the fact is, that in such 

 a case he should sit forward and lean back. 



Both for security of seat and for ability to accommodate 

 himself to the movements of his mount, the rider should 

 be able to bring his weight back with the utmost facility ; 

 but of course without having to alter the position of his 

 thighs and knees, because that has been adopted with the 

 object of obtaining the best possible grip. If we examine 

 the mechanism by which the rider can adjust the position 

 of his centre of gravity, we shall find that the upper part 

 of the body can freely revolve on the lower edge of the 

 pelvis as a pivot (its connection with the legs being main- 

 tained by the hip joints) ; and that a much smaller amount 

 of backward and forward rotation can be obtained by the 

 working of the joints of the spinal column (those of the loins, 

 back and neck). Hence it is well for the rider to sit with 

 his rump well under him, and the pelvis sloped a little to the 

 rear (Fig. 182), in the natural and unconstrained position 

 a man would sit on a chair or stool. The more the rider 

 gets into the saddle, the greater will be the backward slope 

 of the pelvis, and consequently the stronger the seat. If, 

 on the contrary, he sticks his rump out behind him (Fig. 183) 

 instead of sitting on it as he ought to do he will naturally 

 decrease his stability by bringing his centre of gravity for- 

 ward. Any attempt to correct the position of the centre of 

 gravity by hollowing out the back (Fig. 183), can be made 

 only by continued muscular contraction, and would therefore 

 be objectionable. 



As the movements of the horse at each stride, especially in 

 the canter and gallop, tend to cause the rider's body to be 

 jerked alternately backwards and forwards in a manner that 



