Book V. OPERATIONS FOR THE CARE OF LIVE STOCK 525 



3236. The yoking of draught animals requires still more attention than harnessing them. 

 To know when an animal is properly yoked, or placed in proper circumstances to per- 

 form the kind of labour assigned to him, it is necessary to have clear ideas as to the kind 

 of power to be exerted by the animal, whether drawing, carrying, pushing, or two or 

 all of these. The horse and ox draw from their shoulders, carry from their back, and push 

 with their breech. The point of resistance in all weights, or objects to be dragged or 

 pushed along the ground's surface, lies below the centre of gravity ; and in all cases of 

 drawing, a line from this point of resistance to the collar of the animal should form a 

 right angle with the plane of the collar-bone. Hence the necessity of allowing the plough 

 chains from the back of the animal to hang freely, so as to form a straight line from 

 the collar-blades through the muzzle of the plough to the point of resistance. Hence, also, 

 the advantage of yoking two horses in a cart by means of the endless rope or chain already 

 described. (2755.) In yoking animals where the labour is principally carrying a weight, 

 as in carting, great care is requisite that the weight be not oppressive, and that the sus- 

 pending chain move freely in the groove of the saddle, so as to produce a perfect equipoise. 

 Various opinions are entertained as to the weight which a horse can carry with or without 

 drawing at the same time. According to the practice of experienced carters, if a one- 

 horse cart is loaded with 20 cwt., 5 cwt., but not more, may be allowed to rest on the 

 back of the horse by means of the traces, chain, and saddle. This is meant to apply 

 where the roads are level ; in going up or down hill, to admit of the same proportion of 

 weight, the traces, or shafts, or the bearing chain, must be lowered or raised according 

 to circumstances. Yoking animals to push only is a case that seldom or never occurs ; 

 but it will be useful to mention, that, as the line of the breech of animals is nearly per- 

 pendicular to the horizon, and the principle being that the line of exertion should be at 

 right angles to the exerting surface, so the direction of pushing or backing, as it is 

 commonly called, may be a horizontal line, or a line parallel to the surface on which the 

 animal stands. 



3237. The hours of consecutive labour to which animals are subjected form a matter 

 which deserves consideration. The advantage of short stages in drawing heavy loads 

 has been proved by Mr. Stuart Menteath of Closeburn : this gentleman, who is pro- 

 prietor of one of the richest coal fields in the island, both as to quantity and quality, has 

 very successfully employed horse power to the drawing of heavy loads, by dividing the 

 roads into short stages. Before this expedient was resorted to, each horse could travel 

 the distance of only 1 8 miles, and return with a load of 24 cwt. thrice a week ; that is 

 to say, the aggregate of the labour of each horse amounted to 3 tons 2 cwt. weekly : but 

 by dividing that distance into 4 stages of 4§ miles each, 4 horses can make 3 trips daily, 

 and draw a load of 33 cwt. each trip, or very nearly 5 tons daily, or 30 tons weekly. 

 Hence, according to this method, the aggregate of the labour of each horse amounts to 

 about 7 tons weekly. Suppose 16 horses are employed ; instead of making them travel 

 18 miles one day, and return with a load the following, the more advantageous plan is 

 to arrange them in 4 divisions, and make each division travel only 44 miles in succession : 

 were this distance divided into six stages, the load might be proportionally increased, 

 with less fatigue to the horses ; for it will invariably be found that the most profitable 

 mode of applying the labour of horses, is to vary their muscular action, and revive its 

 tone by short and frequent intervals of repose. Were stone rail-tracks laid down on the 

 pulls between Sheriff Hall and Edinburgh, and the above plan adopted with waggons 

 not exceeding 11 cwt. similar to those used by Mr. Stuart Menteath, the inhabitants 

 might be supplied with coal at a cheaper rate than by any other existing mode of con- 

 veyance. Mr. Stuart Menteath considers the same principle equally applicable to 

 ploughing ; instead of 2 yokings, as at present, of 4 hours each, were 3 yokings of 2i 

 hours each substituted, the horses would be less exhausted, and more work accomplished. 

 {Scotsman, Jan. 6. 1830.) 



3238. The labour of a horse in a day , according to Professor Leslie, is commonly reckoned equal to that 

 of five men • but he works only 8 hours, while a man easily continues his exertions for 10 hours. Horses 

 likewise display much greater force in carrying than in pulling ; and yet an active walker will beat them 

 on a long journey : their power of traction seldom exceeds 144 lbs., but they are capable of carrying more 

 than six times as much weight. The pack-horses in the West Riding of Yorkshire are accustomed to 

 transport toads of 420 lb. over a hilly country ; but in many parts of England, the mill-horses will cany 

 the enormous burthen of 910 lbs. to a short distance. The action of a horse is greatly reduced by the 

 duration of his task ; though not encumbered at all with any load or draught, he would be completely 

 exhausted, perhaps, by a continued motion for 20 hours in a day. Though a horse might start with a cele- 

 rity of 16 miles, this would be reduced in 4 hours to VA, and in 8 hours to 5f. Hence the great advan- 

 tages resulting from short stages, lately adopted for the rapid conveyance of the maiL {Ek?nents of 

 Natural Philosophy.) 



Sect. II. Labours with Cattle on the Soil. 



*3239. Ploughing is justly considered the most important of agricultural operations, as 

 on the manner in which this is performed depends the facility of executing all succeeding 

 operations on the same piece of land. The plough acts as a wedge, separating a portion 

 ot the soil, and turning it over at the same time. If this wedge were properly constructed, 



^L 



