534 



ON DRAUGHT. 



into a hole, or stopping against a stone, it requires no profound reasoning to 

 show, that a force pulling upwards in the direction A B, fig. 9, will raise the 

 whole wheel over the obstacle -with much greater facility 

 than if applied horizontally, as A C : this is the only 

 circumstance, unconnected with the horse, that ought to 

 govern the direction of the traces, and the degree of the 

 inclination here must, of course, still be proportioned to 

 the power of the horse. We see therefore that, in pro- 

 portion as the horse is stronger, or that we are disposed 

 to make him exert a greater effort, the traces should be 

 inclined downwards from the collar : with a good average 

 horse, perhaps one-sixth or one-seventh of the distance from the collar to the 

 extremity ; with a horse of inferior capabilities, arising from weakness in the 

 limbs, and not want of weight, or with an ordinary horse when travelling above 

 six miles an hour, the traces should be nearer the horizontal line, except when 

 the circumstance of a rough road, before alluded to, requires some modification 

 of this. To be able to apply these rules generally in practice, it would be 

 necessary to have some means of altering the traces while on the road ; as we 

 have stated that they should be differently arranged according as the road is 

 level or rough, or ascending or descending, this would not be difficult to con- 

 trive, and has, indeed, been suggested by some writers upon this subject ; but it 

 is probable that, except in stage-waggons, where the same carriage goes along a 

 great extent, and consequent variety of road, it will be sufficient to adjust the 

 traces according to the average state of the roads in the neighbourhood ; and 

 we cannot greatly err, if we bear in mind that inclining the traces downwards 

 from the collar to the carriages, amounts to the same thing as throwing part of 

 the weight of the load on to the shafts, a thing frequently done in two-wheeled 

 carts, and a manoeuvre which all good carmen know how to put in practice. 

 The impossibility of inclining the traces of the leaders, owing to their distance 

 from the carriage, is an additional reason to those given before, why they (the 

 leaders) cannot, when required, exert such an effort as the shaft-horse or 

 wheeler ; and on rough cross-roads, is a great argument in favour of harnessing 

 horses abreast. 

 Yet what can be more contrary to the rules here laid down than the injudi- 



Fig. 10, 



oious mode frequently adopted in harnessing horses ? How constantly do we 

 gee the efforts of horses paralysed by misapplication of their respective qualities ! 

 In the annexed sketch, (fig. 10.) for instance, which represents a very common 



