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ON MANURES. 149 



with much apparent advantage by Mr. Curvven, both when 

 applied to the surface soil, and to clay taken from the under 

 stratum. The method is as follows : — 



'Mounds of 7 yards in length, by Sh in breadth, are kindled 

 with 72 bushels of lime; first, a layer of dry sods, or parings, 

 on which a quantity of lime is spread, mixing sods with it, — 

 for he doubts whether clay can be properly converted into 

 ashes without a mixture of surface soil, as it is in that case 

 either calcined, or not sufficiently burned. Then a covering 

 of eight inches thick of sods, on which the other half of the 

 lime is spread, and covered a foot thick ; the height of the 

 mound being about a yard.' 



'In twenty-four hours it will take fire. The lime should be 

 taken immediately from the kiln; but it is better to allow it to 

 ignite itself, than to efiect it by the operation of slaking by 

 water. When the fire is fairly kindled, fresh sods should be 

 applied; and it is recommended to obtain a sufficient body of 

 ashes from the sods befoi^ any clay is put upon the mounds. 

 The fire naturally rises to the top; it takes less time, and does 

 more work to draw down the ashes from the top, and not to 

 sufl^er it to rise above six feet.' 



Mr. Curwen also says, ' That the former practice of burning 

 in kilns was more expensive, did much less work, and in many 

 instances calcined the ashes, and rendered them of no value.' 

 On which it may be observed, that, with regard to the expense, 

 the difference in labour in favour of the practice of burning 

 with lime cannot be very material, for it only consists in the 

 charge of raising the walls, with a little more attention to the 

 fire, and will not amount to so much as the cost of the lime. 



Application. — The chief point to be observed in the appli- 

 cation of these ashes is — that they be thoroughly pulverised, 

 or at least brought into a state as nearly resembling powder 

 as may be found practicable ; and this cannot be effected 

 unless the heat be so confined as to prevent it from spreading 

 to a ffame, for in that case the clay will be assuredly burned 

 to bricks, and to this mistake many failures in experiments 

 have been attributed. The term ^ashes'' may, indeed, in this 

 sense, be deemed somewhat misapplied ; but we know not any 

 other that will more clearly convey our meaning, though our 

 readers will doubtless comprehend, that the process is to stop 

 short of that state of hardness whicii is produced by the brick- 

 kiln. In effecting this, care should be taken not to burn clay 

 that has been much sun-dried, for if put on the kiln in that 



