224 ESTIMATED VALUES FROM CALXING. 



also that the increase of products, as shown in the second course 

 of the rotation (beginning three years after the application), is 

 equal to 100 per cent, on the production previous to marling. This 

 estimate is quite low enough, as all experience has shown. Upon 

 such land, and so treated, this degree of increase may very often 

 be obtained upon the first crop of the first course ; and, even if no 

 auxiliary means of enriching be afterwards used, the rate of in- 

 crease will be more and more for each of sundry succeeding courses 

 of crops thereafter. Then let us test the value of the returns by 

 figures as before : 



First year, product in corn per acre, 20 bushels, at 50 cents . $10 

 Second year, wheat, 10 bushels, at $1 . . . . .10 

 Third year, clover, most of it left as manure to the land, and 

 no present pecuniary profit counted here . . . .00 



20 

 Total expenses of cultivation, &c., as before, in two years . 10 



Net product, or clear profit of cultivation in the term of three 



years . . $10 



This is all so much increase of net annual product upon the pre- 

 vious rate; and the amount, $3.33 yearly, is the interest (at 6 per 

 cent.) of something more than a capital of $55. And therefore, 

 according to these grounds of estimate, $55 per acre is the increase 

 of intrinsic value given to the land by marling alone, or $48 the 

 clear gain made by the operation, after deducting $7 paid for the 

 marling of the land ; and this without regard to what might have 

 been its previous intrinsic value, or its former or its more recent 

 market price. The more rigidly this mode of estimate is scruti- 

 nized, the more manifestly true will be found the results. The 

 premises assumed, in the supposed effects and profits of marling, 

 will not be objected to (unless as being too low) by any person 

 who is well informed by practice and experience. 



But there is one important apparent omission of a proper charge - 

 in the last statement of expenses. This is the increase of labour 

 of tillage, harvesting, &c., caused by the crop being doubled in 

 quantity. This is certainly a fair ground of charge ; and, if esti- 

 mated alone, would serve to reduce considerably the statement of 

 increased net product, and consequently of increased value of land. 

 But there were also omitted sundry items of increased production, 

 which together would undoubtedly much more than compensate for 

 the increase of labour in tilling a deeper and richer soil, and in 

 harvesting, removing, and preparing for sale or use, a double quan- 

 tity of crops. These items of gain are, first, the additional offal, 

 in corn-stalks, fodder, and shucks, and wheat or oat straw and 

 chaff; second, the limited proportion of clover grazed or mowed ; 



