134 A PRACTICAL TREATISE 



outsides, which remain unburnt, are then ag-ain heaped tip 

 whilst sufficiently on fire to be consumed. Thus all the soda 

 are burned equally, but as lig'htly as they can be to be reduced 

 to ashes. 



In some instances circular heaps have been formed over 

 laro-e roots to the extent of 54. feet by 20, and found com- 

 pletely successful. The manner of forming these clamps was 

 thus: — a quantity of large roots was laid upon the ground, and 

 inclosed by a wall of sods three or four feet high, and at the 

 bottom of each side wall were six openings, about twenty 

 inches square, in which faggots were laid, so as to connect 

 with the roots. When the inclosure was filled with sods, and 

 the clamp raised to the height of eight feet, twelve fires were 

 all kindled at the same time, and, in less than forty-eight hours, 

 the whole mass, containing 400 cart-loads, was entirely burnt 

 through to the top; by wiiich mode of burning it has been 

 computed that the ashes cost no more than threepence per 

 cart-load of sixteen bushels. 



The most common method, indeed, is to form the heaps 

 about a yard in diameter, like small hay-cocks, a few yards 

 apart, the sods set edgeways, with a bough of furze at the 

 bottom, covered with some of the driest turf, keeping the sods 

 on the inside as hollow as may be, but laying them fiat and 

 close on the outside to keep in the heat. The heaps made in 

 this manner are kindled usually with a link made of tow 

 dipped in tar, and wound round a small stake, the lighter 

 running along the rows from heap to heap, and lighting them. 

 Some skill is requisite in their formation, for, if the heaps be 

 made too large at first, their own weight crushes them down, 

 and destroys the necessary openness of the inner side, while, 

 if too small, the fire, not being sufficiently confined, flies out- 

 ward, and spends itself prematurely ; yet, if the sods in the 

 small heaps are damp, the force of the fires is so soon ex- 

 tinguished, that heaps of four and five cart-loads have been 

 found insufficient; and to this want of precaution in the pre- 

 paration of the ashes has been partly attributed the defects 

 which some persons have assigned to the practice itself Yet 

 the weather is sometimes so unfavourable that means must 

 necessarily be taken for increasing the heat of the fires, for 

 which purpose a very simple apparatus has been contrived in 

 Scotland. It is put together with merely a few small old iron 

 hoops, the halves of which are placed so close together as to 

 prevent the sods from falling through, and riveted to iron rods 



