STUBBLE. 



force tending to wrench it asunder by torsion. 

 Mr . H. 'e following results of 



bis experiments on the resistance of a crush- 

 ing force of shorl pillars of some of the most 

 .-riptions of wood, the force being 

 applied in the direction of the fibres. 



IDLE. The root ends of the culms of 

 corn left in the field, standing as they grew, 

 after ihe corn has been reaped by the sickle or 

 scythe. In some parts of England only a small 

 portion of the straw is cut off with the ears of 

 corn, and the stubble in that case is a foot or 18 

 inches in length ; but in others the corn is cut 

 a* close to the surface as possible, in which 

 ease ibe stubble is quite short. In general, 

 long stubble is a symptom of bad farming, be- 

 cause a quantity of straw is in this case left to 

 waste in the field, which might have been car 

 ried home and rotted into manure. 



In botany, is that elongation of the 

 ovarium which supports the stigma. It is an 

 extension of the midrib of the carpellary leaf, 

 or is formed by the rolling up of the attenuated 

 extremity of the latter. 



SUBSOIL-PLOUGH (PI. 17,o, g). See 

 PLOPOH and SCBHOIL-PLOUGHIXG. 



SUBSOIL-PLOUGHING. In farming, the 

 operation of breaking the substratum by means 

 of a plough constructed especially for that pur- 

 pose. Considerable discussion has taken place 

 with regard to the advantages of subsoil-plough- 

 ing; adiflerenceof opinion whichappearstohave 

 been principally caused by an inattention to the 

 chemicalefTectsproducedbythesubsoil,orDean- 

 stonizinsr system of tillage, so named from being 



SUBSOIL-PLOUGHING. 



time, by the action of the atmosphere, and per- 

 haps by a partial mixture with the surface- 

 mould, rendered sufficiently friable and fertile. 

 It is of necessity a consequence of this subsoil- 

 ploughing, that the permanent drains of all 

 lands thus cultivated must be constructed rather 

 deeper in the soil than is usual with farmers ; 

 the top of those at Deanston are placed at a 

 depth of 22 inches from the surface, so as to 

 be completely out of the way of the subsoil 

 which the plough has turned over. 



As the description of this valuable plough 

 cannot be too generally circulated, I will here 

 introduce it in Mr. Smith's own words : 



"The subsoil-plough has been constructed on 

 principles appearing the best fitted to break up 

 the subsoil completely to a depth sufficient for 

 thorough cultivation, say 14 to 16 inches, whilst 

 the active soil is still retained on the surface; 

 to be of the easiest possible draught in refer- 

 ence to the depth of furrow and firmness of the 

 subsoil ; to have strength and massive weight 

 sufficient to penetrate the hardest stratum; to 

 resist the shocks from fast stones, and to throw 

 out all stones under 200 Ibs. in weight. All 

 this has been accomplished and practically 

 proved at Deanston, over an extent of at least 

 200 acres of various soils; and also in various 

 parts of England, Scotland, and Ireland, during 

 several seasons. The plough requires 4 good 

 horses, an active ploughman, and a lad to 

 drive the horses and manage them at the turn- 

 ings. Six horses, yoked three and three abreast, 

 may be necessary in some very stiff or stony 

 soils. A common plough, drawn by two horses, 

 goes before the subsoil-plough, throwing out a 

 large open furrow of the active soil ; the sub- 

 soil-plough following, slits up thoroughly and 

 breaks the subsoil, and the next furrow of 

 active soil is thrown over the last opened fur- 

 row of the. subsoil; the stones brought to the 

 surface by the subsoil-plough being thrown 

 aside on the ploughed part of the land by a lad: 

 thus the work proceeds until the whole field is 

 gone over. The lad should carry a bag of 

 wooden pins, that he may mark the site of the 

 large fast stones which the plough cannot throw 

 out, and which must' afterwards be dug out 

 with the pick, and perhaps blasted. 



" The charge of subsoil-ploughing a Scotch 

 acre may be estimated at 24s. or 30s. per statute 

 acre, being one-fifth of what a similar depth 

 with the spade would cost, and, upon the whole, 

 as effectually done. When land which has 

 been opened up by the subsoil-plough shall 

 have undergone the first rotation of cropping, 

 several inches of the subsoil may be taken up 



first employed, or at least first brought into gene- by the plough to mix with the active soil; and 



raln<>- M s rnith,of Deanston, in Stirling' 



shin-, when he was examined, in 1836, before 



in proportion as the subsoil is ameliorated, so 

 may the greater depth be taken up with advan- 



the Agricultural Committee of the House of tage. In the richer subsoils it is sometimes 



By this system, by means of a sub- expedient to plough to the whole depth of the 

 il plough, of which there are several kinds, 'moved subsoil on the first application of the 



the subsoil, or under crust of earth, is merely trench-plough. The trench-plough recommend- 



broken and pulverized, say to the depth of from ed for this process should be made in the form 



) inches, without being brought to the ofWilkie's plough, having all its dimensions 



surface, or mixed wiih the upper soil; after a made of double size; or, what is found to an- 



'apse T4 or 5 years, a portion of the previously swer fully as well, by a plough in the fashion 



substratum is found, by experience, of the old Scotch plough, but also of double 



3 be advantageously (by deep plough- dimension.,. Such ploughs require six horses, 



the surface; it being in this yoked three and three abreast, with one man to 



