420 



ON DRAUGHT. 



There is also a time, when incliiiin>^ the traces downwards is almost in- 

 dispensable : it is when dragghig a four-wheeled waggon over a rough 

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

 obstacle by falling into a hole, or stopping against a stone, it requires no 

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

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

 obstacle with much greater facility than if applied 

 horizontally, as AC ; 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 proportion 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 hori- 

 zontal 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 dif- 

 ferently arranged according as the road is level or rough, or ascending 

 or descending, this would not be difficult 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 ex- 

 tent, 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 re- 

 quired, 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 



