196 BITS AND BITTING. 



as the mouthpiece does, and is usually graduated 

 throughout, but it will evidently suffice to do this with 

 the fourth and fifth inches. 



It is scarcely necessary to point out that if this gauge 

 "be placed in the horse's mouth like a bit, with the bar 

 a 1} at exactly the proper point (opposite the chin- 

 groove), the fixed cheekpiece c d being then held gently 

 up to the off side of the mouth (the operator facing the 

 horse's forehead), the sliding one ef may be shoved up 

 just close enough to the cheek, at the near side, not to 

 displace the lips; and then fixing it with the screw, 

 and removing the gauge, we can read off the dimension 

 of the width of our mouthpiece from the scale engraved 

 on a b. 



The figure shows further a rod g h fitted to slide up 

 and down the movable cheekpiece e /, which is grad- 

 uated into inches and eighths or tenths on its lower 

 limb. This contrivance enables us to measure the 

 height of the bar of the mouth, which is done in the 

 following manner: The instrument, adjusted to the 

 proper width of the horse's mouth, is placed as before, 

 with the bar a b exactly opposite the chin-groove, but 

 underneath the tongue, and is then wheeled round on 

 its own axis till the upper limbs of the cheekpieces 

 stand nearly perpendicular to the general line of the 

 horse's nose. This, of course, brings its lower limbs 

 in the opposite direction towards the neck, and the 

 rod g h is then gently shoved up till it presses lightly 

 into the chin-groove, taking care that the gauge stands 

 square, and that the mouthpiece lies equably on both 

 bars of the mouth. The rod g h is then screwed fast, 

 whilst the screw of the cheekpiece e f is loosened alto- 

 gether, so that the latter may be removed without 



