TAKING MEASURE FOR THE BIT, ETC. 201 



as the mouth-piece 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 b at exactly the proper point (opposite the chin- 

 groove), the fixed cheek-piece 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 mouth-piece from the scale engraved 

 on a b. 



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

 and down the movable cheek-piece e f, which is gradu- 

 ated 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 cheek-pieces stand nearly per- 

 pendicular to the general line af the horse's nose. This, 

 of course, brings its lower limbs in the opposite direc- 

 tion 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 

 mouth-piece lies equably on both bars of the mouth. 

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

 cheek-piece e f is loosened altogether, so that the latter 

 may be removed without disturbing the rod g h ; we 



