ON MANURES. I45 



that of burning-. They are, therefore, usually formed in the 

 very field on which tlie clay is to be laid, and out of which it 

 is dug; in which case they may be made entirely with sods, 

 or mud and straw, in the following" manner : — 



On a headland or waste piece of ground, off which sotls can 

 be procured with sward sufficiently tough to build a wall, 

 erect an oblong or a circular inclosure, about eiglit or ten feet 

 in diameter, and two feet thick, but not higher than three or 

 four feet On a level with the surface of the ground, cut 

 flues, opening through the opposite sides of the wall, so that 

 they may all meet in the centre of the kiln; make them also 

 about five or six inches deep and four wide, and let them be 

 covered wilh sods on the top, so as to keep them free of 

 clay and rubbish, and the mouths well open to the air. Then, 

 in the centre of the kiln, place brushwood, turf, or any com- 

 bustible, with some blocks of wood to strengthen the fire, and, 

 when all is well kindled, throw on some culm — if you have 

 any — and then clay, and so on, adding clay to the heap as the 

 fire may be found sufficiently strong to take the dressing; 

 always observing to keep the heat of the kiln as even and as 

 moderate as possible, — ^just of sufficient strength to expel the 

 moisture from the layers of clay as they are laid on. Much 

 care should also be taken not to cover the fire too soon after 

 being lighted, as that might extinguish it totally, and therefore 

 the clods first put on should be of the largest description, that 

 spaces may thus be left for the free admission of the heat. 

 The smoke must be prevented from escaping; but the progress 

 of the fire, as it ascends, may be ascertained by occasionally 

 thrusting a finger here and there through the surface; to 

 which, if it has approached very near, more matter must be 

 added. 



The walls, when made of sods, should be beat close with the 

 spade, in order to prevent them from drawing air, by which the 

 burning of the clay would be much retarded; the kiln may 

 then be immediately lighted; but if made with mud and straw, 

 they should be permitted to dry before the fire is kindled. 

 They should not, at first, be built higher than three to four 

 feet, nor the inclosure be wider than ten, because the earth can 

 then be flung easily over every part; the fuel will also be thus 

 more easily placed, and the firing more conveniently managed. 

 As it is not necessary that much neatness should be observed 

 in the construction, a kiln of this size may be erected, under 

 proper directions, by five or six men in the course of a day. 



