278 THE HORSE IN SERVICE 



ence of two horses in, his team. In order to exert equal pressure 

 on both sides of each mouth, the relative carriage of heads, 

 promptness in driving, disposition, etc., of both horses must be 

 taken into consideration. With a pair of horses closely matched 

 in every way, the coupling reins should be from four to six 

 inches longer than the draught reins, since they are the hypo- 

 theni of triangles. If one horse carries his head higher than the 

 other, his coupling rein should be on top in order not to be borne 

 down upon by that of the lower headed horse. If one- horse sets 

 his head and neck in a flexed position, his rein should be short- 

 ened to take up the slack so« producnd. Or if one drives more 

 freely than the other, his rein must be shorter to keep- him under 

 restraint without pulling the other horse. In order, however, 

 to keep the horses' heads an equal distance apart and their bodies 



D N N' 



Fig. 1-JS. — The adjustment of the coupling reins is shown by the dotted lines. 



parallel w ith the pole, whatever is taken up in one rein must be 

 let out i a the other. Having the coupling reins too short draws 

 the heads together and throws the horses out from the pole, some- 

 times causing them to fall, on pavements and down grades. Too 

 long coupling reins turn the heads out and the bodies in against 

 the pole. 



Fig-ure 148 illustrates by solid lines the position of the reins 

 when the horses carry their heads and necks alike, AB and CD 

 jepresenting the bits of the two horses, AM and BN the draught 

 reins, BN and Cilf the coupling reins. If, however, the off horse 

 carries his chin in, or for other reasons requires his rein to be 

 shortened, the altered position of the coupling reins is shown by 

 the dotted lines. Coupling rein BN is taken up on the draught 

 rein to N^, the take back on the draught rein to A^ being made 

 by the hand of the driver. This, however, would shorten coupling 



