310 The Book of the Horse. 



English in the small book already quoted, by Major Dwyer. The following passages abridged 

 or paraphrased from the Major's work equally apply to the bridles of riding or driving horses : — 



" On looking into a horse's mouth it will he seen that the lower jaw consists of two flat, 

 irregularly-triangular cheek-bones, whose anterior branches form the channel in which the tongue 

 lies, enclosed towards the root, between the two rows of molar (grinder) teeth, further by those 

 portions of the jaw or gums that lie between the point where the grinder teeth cease, and the 

 incisors (cutting teeth) commence, which is known generally as the bars, that is, the gums ; on 

 the lower portion of tlic bars the tusks are to be found in male animals. 



" It is of the utmost importance that the curb-bit should be laid on the proper point of 

 the bars, where alone it can have the most effect, and do no harm. (See illustration at 

 page 308.) 



" There is a military rule of thumb for placing the bit (as distinguished from the snaffle) at 

 a certain height above the tusks, but as mares have no tusks this is an imperfect rule, not 

 worth attending to, when Nature has provided an infallible mark for showing where the curb- 

 bit should be placed." 



" The lower surface of the lower jaw is covered with a very thick skin, underneath which 

 lie the roots of the beard, fat, and membrane. This structure is continued up into a certain 

 depression under the chin, called by the Germans the curb-groove : the bone beneath the thick 

 skin of the chin-groove is flat, and rounded off in all directions." A flat curb-chain, not too 

 wide for the groove, may be applied, by the action of the bit, with a sufficient amount of 

 pressure to control, without hurting the horse. If the bit is placed in the mouth exactly over 

 or opposite the chin-groove, and a curb-chain is linked to it at a proper length, the instru- 

 ment will infallibly fit into its proper place, to be acted on by the action of the hands on the 

 reins. 



But to make the best of a horse's mouth, it is absolutely necessary that a point should 

 be attended to which is almost universally overlooked in this country — i.e., the bit should fit the 

 horse's mouth. 



" There are three dimensions of the interior of a horse's mouth, which should be accurately 

 ascertained before attempting to fit him with a proper bit, in addition to the size of the 

 tongue, if a port is used. The first and most important is the width of the mouth from side 

 to side, measured opposite the chin-groove, including the thickness of the lips. If that is too 

 narro'w, the lips are liable to injury, or to be squeezed up so as to cover the bars, and thus 

 neutralise the action of the instrument. If too wide, the bit slips from side to side, displaces 

 tlie port from its proper position, and renders it impossible to accurately fix the length of the 

 curb-chain." 



" The port is the arched portion of a curb-bit, intended to make the pressure rest on the 

 bars instead of partly on the tongue. 



" The second measurement is of the width of the channel in ivhich the tongue lies, in order 

 to settle the proper width of the port, the remainder having to be reserved for the bars. 



" The third dimension is the height of the bars, that is, the distance between the surface of 

 the bars, naked gums, and the undermost point of the chin-groove." 



All this sounds at first very complicated, and these measurements are only necessary when 

 a valuable horse presents difficulties in the way of fitting him with a bit ; but the principal of 

 these measurements have been brought to the following averages by the experiments of Colonel 

 Von Weyrother with a simple instrument (see the illustration on j). 309, half the original size), 

 by which the operation of measuring is easily performed. 



