120 



ON DRAUGHT, 



There is also & time when incliiiinn; the traces downwards is almost 

 indispensable: it is when dragging a four-wheeled waggon over a rough, 

 broken road. If the front wheel, which is generally small, meets with aii 

 obstacle by falling into a hole, or stopping against a stone, it requires nc 

 profound reasoning to show, that a force pulhng upwards, in the direction 

 AB, Jig. 9, will raise the whole wheel over the ob- 

 stacle with much greater facility than if applied 

 horizontally, as AC; this is the only circumstance, 

 unconnected with the horse, that ouglu 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 proportion as the horse is stronger, or that we arc 

 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 cir- 

 cumstance 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 ditlerently arranged, according as the 

 road is level or rough, or ascending or descending, this would not be diffi- 

 cult to contrive, 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 neigiibourhood ; and we cannot greatly err, if we bear in mind that, 

 inclining the traces downwards from the collar to the carriage, 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 gooa 

 cartmen know how to put in practice. The impossibility of inclining the 

 traces of the leaders, owing to their distance from the carriage, is an addi- 

 iional reason to those given before, why they (the leaders) cannot, when 

 required, exert such an eflbrt m- the shaft-horse or wheeler; and on rough 

 cross-roads, is a great argumcn; n favour of harnessing horses abreast. 



Fig. 10. 



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

 injudicious mode frequently adopted in harnessing horses? Hcav coi) 



