102 On Agricultural Mechanics. 



proposed by Mr. Smith — the frequent-drain system. This con- 

 sists in cutting parallel drains at intervals varying from a half to 

 one-eighth of a chain, and of proper depth, and in conveying the 

 water from them to a proper outlet by means of a larger main 

 drain, into which they all run. 



In the great majority of cases land is such that, in the cutting 

 of drains, the spade, and often the pickaxe, is required ; and in all 

 cases the most efficient drainage is that performed by the hand. 

 The ditches, however, in those rare cases where the subsoil is 

 clayey and free from stones, as in alluvial soils^ may be cut by an 

 implement which turns out the whole of it, or nearly all of it, at 

 once. The first mention I have seen of such an implement, 

 which, however, seems only to have been applied to the cutting 

 of grips or surface-ditches, is in Mr. Douglas's report of Rox- 

 burgh and Selkirkshire, 1813, in which he speaks of " a kind of 

 instrument or plough which cuts and removes a square foot of 

 earth ; and with six horses and five men will drain a greater 

 extent in a day than 100 men." This, it seems, did not obtain 

 general use : since, however, Mr. Smith gave such an impulse to 

 the adoption of a system of thorough drainage, a plough for the 

 purpose of cutting out a trench has been invented by Mr. Mac 

 Ewen, of Blackdub, in the Carse of Stirling, where it is much 

 employed. Though I have seen this implement, I never saw it 

 at work ; but it is said to answer admirably on the soft alluvial 

 clay of the Carse, and testimonials have been received by the in- 

 ventor, which show that by perseverance in its use it has answered 

 well also on the more indurated and stony clays of the hilly land 

 in the neighbourhood. 



Great force is required to work this implement ; ten or twelve 

 horses, with a man to each pair, are required, besides two men to 

 work the plough. The cost of this, with the tear and wear of the 

 implement, is estimated at 3/. \2s. per day, viz., the horses at 

 4^. a-day, the men at 2s., and the tear and wear of the plough 

 at 1*. per horse. It will cut out 520 roods of 36 yards in a-day, 

 which gives 2d. per 36 yards as the cost : this is not one-twelfth 

 part of the cost of digging with the spade. The trench thus 

 formed is of great width ; but as the same plough may be applied 

 to replacing the furrow turned out, this does not signify. Before 

 filling in the stones or placing the tiles, a man with a small spade 

 forms a space for them, and corrects any deviations from the 

 uniform fall of the bottom. This space of perhaps 4 or 6 inches 

 in depth, added to 20 or 22 inches, the depth of the furrow turned 

 out, makes the whole depth of the drain rather more than 2 feet. 

 This is one of the most successful of the many attempts which 

 have been made to diminish the expense of cutting drains. 



The mole-plough, the action of which consists in making a 



