48 QUESTIONS OF PRINCIPLE 



into use on the farm, with an estimated effective life of 

 fifteen years, is 5 per annum. 



Depreciation of the Farm Tractor and its allocation is 

 a matter which still requires investigation before any clear 

 rule can be laid down. There are as yet no data as to the 

 life of the various makes of tractor now on the market upon 

 which to base a charge for depreciation. It will be wise 

 to assume that the effective life of all of them is short, and 

 until more exact information is forthcoming, to write off 

 the cost over a short term, say five years. Allocation of 

 depreciation must also be the subject of further consideration, 

 but in the meantime the most obvious course is to apportion 

 it on the basis of fuel consumption ; a light load accompanied 

 by a relatively low rate of fuel consumption may not un- 

 reasonably be supposed to induce a corresponding rate of 

 wear and tear, but there may be other factors involved, 

 such as the relative effect of stationary and locomotive 

 working under equal loads. These are matters about which 

 nothing is known at present, and the fuel consumption basis 

 of allocation may serve until a better can be substituted. 



Manurial and Food Residues. In calculating the value 

 of these items the basis, once again, must be the cost. The 

 principle is to take the initial food cost, and to depreciate 

 it according to the methods laid down by agricultural 

 chemists. (See, for example, the tables of Lawes and 

 Gilbert, as revised by Voelcker and Hall.) The fact that 

 the conditions of making and storing farm-yard manure, 

 and that the influence of atmospheric and soil conditions 

 upon the effect and duration of it and of artificial manures 

 too may produce wide differences in their action is inevitable, 

 but no better principle has been devised, though chemists 

 differ amongst themselves as to figures. It may be noted 

 that whereas in an outgoing valuation the valuer for the 

 landlord (or incomer) may justifiably claim to substitute 

 the price at which the manures or foods could have been 

 purchased for that at which they were actually bought,, 

 and this, indeed, is commonly done, the farmer keeping 

 records of his transactions must not depart from his own 



