VARIOUS METHODS OF HEATING DESCRIBED IN DETAIL. 235 



there being more room for the exercise of skill in their produc- 

 tion. 



Suppose, for instance, that we take the calculations of Mr. 

 Allen, in his treatise on the Culture of the Grape-vine, where, 

 in pp. 69, 70 and 71, he estimates the quantity of fermenting 

 manure, necessary for the covering and warming of a border 

 100 feet in length to cost $700; which, together with the 

 other items of management, repairs, fuel, interest on cost, 

 etc., to amount to $1120. The produce of a house so 

 heated and managed, according to his calculation, is on an 

 average 1067 pounds of fruit. I do not intend to dispute the 

 accuracy of these calculations, although they appear startling 

 enough. And doubtless Mr. Allen has had data sufficiently 

 accurate and authoritative, from which to draw his deductions ; 

 and hence I consider myself justified in making them partially 

 the data of mine. 



And, admitting the beneficial effect of fermenting manure to 

 be all that its advocates claim for it, let us compare the calcula- 

 tions above, with the cost and working of chambered borders ; 

 and, by balancing the two together, we shall be the better able 

 to estimate the merits of each on the score of economy. 



In order to effect this, I have been at some pains to obtain the 

 probable expense of such a border as that represented on page 

 232, Fig. 49 ; and, in making my calculations, I have placed my 

 figures rather above than under the estimate ; so that, should 

 I make any error, it will be on the most favorable side. 



To make a chambered border 100 feet long, we have 



For brick work, $200 



Timber to form the bottom of the border, .... 60 



Tank, 50 



Extra piping for do., 10 



Extra fuel, 15 



Excavating the border, 45 



Shutters, &c., for covering do., 100 



$480 



Now, if we subtract 480 from 700, (the cost of manure,) we 

 have a saving of $220, the very first season ; or, in other 



