1837] 



FARMERS' REGISTER 



IJfT 



Effects of burnt day. 



From tliis we should be Icil to conclude that a 

 very inaterial cliHeronce would be Ibuiid to exi^t 

 in earth thus im-rely ih'ied ; lor there can be no 

 doubt thai its properties must depend upon the 

 quantity of vefjetaiiv-e matter which itcoalains. 

 But it is diliii-ull to draw the line between this pro- 

 cess ol" torreliiction, and that which consists in 

 buruintr theeartii to asties; lor ifthe clay be merely 

 dried, 'he next rains will reduce it back to its former 

 state, by which the soil cannot be benefited; and 

 if the fire be advanced to a decree much stronger, 

 it will probably have the effect of consuiDing the 

 earth to ashes, in the qualities of which no percep- 

 tible dirt'erence will be Ibund. In the latter stale, 

 indeed, we are strongly of opinion that its efi'ects 

 are purely mechatiical — acting upon heavy soils 

 nRM'plv bv correcting their tenacity, and rendering 

 them less stul)i)orn; but tliis will doubtless conlri- 

 'bute greatly to their lertility, though it cannot be 

 considered as a nutritive manure. 



The stress which has been laid upon the sup- 

 posed value of some kinds of burned clay, incon- 



I sequence of the calcareous matter contained in the 

 subsoil, is probably over-rated; ibr it is seldom 

 found, in soils of that description, in such abun- 

 dance as to be of much service as a manure to 



I other lands. We learn, indeed, from an experi- 

 ment ofGeneral Beatson, that when even the sur- 

 face-soil has been burned, no difference was Ibund 

 between the ertects of that, although containing 

 vegetative matter in the sward, and the ashes of 

 common clay; though the quantity applied was 

 perhaps too small to warrant any positive conclu- 

 sition *. We, theref)re, think that the ideas 

 which have been entertained of the effects of this 

 manure, are rather too sanguine; and we are deci- 

 dedly of opinion that the exj)eciatinns of those of 

 its advocates who imacine that 'burnt clay will 

 surpersede the dung-cart' will be disappointed. 

 It appears, indeed, from a more recent essay by 

 Mr. Burroughs, on the cultivation of white crops, 

 that he has not been so well satisfied of its good 

 effect as to persist in its use instead of farm-yard 

 manure; for although we there find him recom- 

 mending the use of the latter, he yet makes no 

 allusion to burned clay. In Scotland, also, where 

 the burning of clay was a ['^^vf years ago very ex- 

 tensively practiced, we learn that it has since fal- 

 len into considerable disuse. There can however 

 te no doubt that clay ashes may be beneficially 

 used ; but it does not appear from past experience 

 that they can preclude ttie use of lime on soils not 

 formerly dressed with it. 



We make no apolofjy for the length of these 

 extracts, for the subject is of great importance, 

 and although we entertain doubts of the accuracy 

 of the inferences drawn trom the experiments by 

 some writers, yet that should not prevent any far- 

 mer who possesses the means of satisfying him- 

 self by similar trials, from ascertaining their effect 

 by actual practice. It is true, that the nature of 

 some soils does not admit of it; in others, the land 



* Part of a field of eia;ht acres was manured with the 

 ashes of stiff soil burnt in a kiln, and another part with 

 ashes obtained by paring and burning, at the rate of 

 20 cartloads per acre. The whole field was drilled 

 with wheat, and the crop was excellent; but no ditfer- 

 ence was perceptible at the time of growth, nor at tliat 

 of reaping. New System, &c., second edition, p. 159. 

 Vol. V— 18 



is in many cases so valuble, that almost every 

 inch of it is in profitable use; and as it requires 

 about 150 s(pjare yards of surface, six inches deep, 

 l()r a single acre, or a pit of pro[)ortionate size, if 

 dug fi-om the suiisoil, many persons will naturally 

 grudge the sacrifice; though banks and headlands 

 — something, in short, in the shape of waste — • 

 may be fbund on every liiruj. Every one who 

 has the opportLiiiiiy should give it a fiir trial ; and 

 if the result should prove its efficacy, it may then 

 indeed, be considered 'as opening a new field to 

 the prosperity of agriculture.' The ii)llowing are 

 the most ap|iroved methods of preparation, when 

 pits are dug from the subsoil; but if the earth be 

 taken fi-om the surface, then those directions will 

 be applicable which have been already given in 

 the previous chapter; under the head of 'Paring 

 and Burning.' 



Clay-kilns. 



There are two modes of burning clay commonly 

 employed, one by kilns parlly constructed of ma- 

 sonry, and the other of sods; in both of which the 

 earth is piled upon them, instead of being placed 

 untler cover, as in a lime-kiln. 



The kiln of the former kind, described by Mr. 

 Burroughs, should be built in a pit excavated out 

 of the ground which is to be burned, and consists 

 of an arch about lour or five feet long, three wide 

 and two high, made with brick; the front close 

 like an oven, and the inside fitted to receive a 

 strong fire of coals. On the top of the arch six or 

 eight holes are left, the size of a small brick, to ad- 

 mit the heat pa^^singout, which is to communicate 

 to the earth laid on. When the fire is sufficiently 

 strong, the door of the kiln is to be well stopped 

 and the earth thrown on in some degree pulver- 

 ized, about six or eight inches thick, so as to cover 

 the top of the kiln, and every direction round it to 

 which the heat miuht communicate. In this man- 

 ner it is to be dressed alternately with culm and 

 earth, which are to be laid on according to the heat 

 of the fire, which is on no account to be allowed to 

 burn too strong. 



After the kiln is once lighted, it will burn seve- 

 ral hundred bushels of earth without any addi- 

 tional fire inside; and the same kiln will answer 

 for a length of" time to renew the process when 

 necessary. 



The kiln used by General Beatson, which 

 burns 250 cart-loads of 16 bushels each, was sub- 

 sequently erected upon a more scientific principle; 

 but as the fjrm and construction cannot be fijily 

 comprehended without an engraving, we here in 

 sert the plan, elevation, and section. [See next 

 page.] 



The iron floor, formed in the manner of a grid- 

 iron, by transverse flues which convey the heated 

 air immediately under the clay, has been fbund 

 necessary in kilns of largedimensions, but in those 

 of a smaller size thay may be dispensed with; and 

 an arch, or main flue, passing from the furnace to 

 the back of the kiln and having a chimney at the 

 flirtherend, will answer the purpose. 



The site of the kiln, which is dug out of the 

 ground, should be as near as possible to the ma- 

 terials that are to be calcined. Steep, sloping 

 banks, in which the furnace can be placed low, are 

 evidently the best situations, because the lower the 

 furnace the deeper may the excation of the body 



