406 ON DRAUGHT. 



To enter into all their respective merits, and to weigh their comparative 

 advantages under all circunistances, would involve us in many questions 

 foreign to our immediate point of consideration, and would embrace sub- 

 jects which may supply matter for future consideration well worthy of our 

 attention. It is sutHcient for our present purpose to show tha,t there still 

 exist great objections to the universal application of machinery to draught, 

 objections which do not equally apply to the use of animal power; and on 

 the other hand, that there are many advantages in the latter, which are not 

 yet obtained by the former; and that animal power continues, for all the 

 ordinary purposes of traffic upon common roads, to be the most simple in its 

 application, and certain in its effect. 



We shall confine ourselves particularly to the consideration of that part 

 of the question which relates to the slow transport of heavy goods, as being 

 the most important branch of the subject, especially for agricultural pur. 

 poses. Economy is, of course, the grand desideratum in the consideration 

 of this question; consequently, the comparative expense of the two powers, 

 supposing them for the moment equally convenient and applicable, will 

 first demand our attention. 



A difficulty arises here, however, from the want of a certain measure of 

 comparison. The power of a one-horse engine is by no means exactly 

 the same thing as that of a horse. As we have before stated, the mode of 

 applying them being dillerent, the variations in the results are different, 

 and consequently the effects do not bear a constant proportion to each 

 other, under different circumstances; we must therefore be careful not to 

 fall into the mistake which we have ourselves pointed out as a very com- 

 mon source of error, viz: the drawing general conclusions from data 

 obtained in a particular case. We shall take the power of the horse, and 

 that of the steam-engine as ascertained practically on railways, where the 

 effect of each is less influenced by accidental circumstances, and conse- 

 quently can be better ascertained than on a road. We shall confine our 

 calculations of expense to this particular case, and then endeavour to 

 discover how far the same results are to be expected, or what modifications 

 are likely to take place, and what alterations are to be made in the results 

 under difTerent circumstances. As regards the first, viz: the comparative 

 cost of animal and mechanical power on a railway, we cannot do better 

 than quote the words of the late Mr. Tredgold upon this subject, and we 

 accordingly extract the following from his work upon Railways: 



"The relative expense of different moving powers for railways is an 

 interesting inquiry, and the same materials being necessary to estimate 

 the absolute expense for any time or place, it is desirable to give some 

 particulars, to aid the researches of those who wish to make such com- 

 parative estimates. The annual expense of a horse depends on — 



" 1. The interest of purchase-money. 



"2. Decrease of value. 



" 3. Hazard of loss. 



"4. Value of food. 



■'5. Harness, shoeing, and farriery. 



"6. Rent of stabling. 



*'7. Expense of attendance. 



''According to the average duration of a horse in a state fit for labour, 

 of the description required on a railway, the first three items may be 

 estimated at one-fourth of the purchase-money; the food, harness, shoo- 

 ing, &c., included in the 4th, 5th, and 6th, will most likely not exceed 

 40/. per annum, nor yet be much short of that amount; and supposing 

 one man to attend to two horses, this would add 15/. 12^. if the man's wages 



