during the last Four Years. 177 



moncl has also applied peat, cut into the circular shape of tiles, for 

 the same purpose. There is a method of draining; grass-land called 

 wedge or sod draining, fully described by Mr. Handley Brown in 

 our last Number ; in which the roof of the drain is supported by a 

 mere wedge of the natural turf. It is exceedingly cheap, costing 

 in Lincolnshire only 18s. 6cL per acre, at an interval of about SO 

 feet. I think it must require a strong clay subsoil, as a weak 

 clay would hardly maintain an open passage, but would probably 

 silt in. It is, I believe, an old practice in North Wiltshire, 

 where such drains are executed at a depth of 20 inches for 9^. or 

 lOs. the furlong, so that grass-land is there drained at the very 

 narrow interval of 16 J feet for the trifling expense of 21. per acre. 

 Mr. Brown advocates the use of these thorn-drains on arable 

 land also, and states that he has known them draw well where 

 the water has lain over tile-drains. But in thorn-draining-, sooner 

 or later, the whole work must be done again. Tile-drains are 

 made once for ever, since any occasional repairs would fall into 

 the common management of the farm. His statement, however, 

 that tile-drains will not draw on his land, deserves great attention. 

 I have seen the same failure here in drains only 20 inches deep, 

 on some very strong land ; but the clay from the subsoil had been 

 thrown back on the tiles in these drains. In the next field, 

 though the drains were 30 inches deep, yet being covered slightly 

 with stones, and filled in with surface mould, they ran well even 

 after one strong summer rain. Some high authorities tell us 

 that the clay should be pressed down on the tile, and that no 

 water should penetrate the drain from above ; but I must say on 

 this much-argued question,, that practice, I think, is against them. 

 Still Mr. Brown is no doubt right in saying that there is some 

 land in England so extremely retentive of water, that there may 

 be a doubt whether it can be drained with tiles ; and as it is on 

 such land that the expense of tiles is heavy, from the necessary 

 nearness of the drains, it may be well to use the old system of 

 filling with thorns as has been long practised in Suffolk. There 

 the drains are cut to the full depth of 30 inches, a narrow open 

 channel being left at the bottom in the solid clay, a twisted rope of 

 straw forming the roof with thorns or heath over it. This system 

 has been found to answer; and indeed on the strongest clays ap- 

 pears to afford more certainty that the drains will run than the 

 new plan of tile-draining. They last sixteen years, and may be 

 completed for lO^-. a furlong, so that 6 furlongs of drains may be 

 allowed to the acre — that is, the drains may be placed so near as 

 even 11 feet to each other — for the trifling expense of 3/. It 

 appears to me a fortunate circumstance that on those very heavy 

 soils where on the one hand the great number of drains which is ne- 

 cessary might raise the expense of even cheap tiles beyond ordinary 

 means, and on the other hand there is some doubt whether tiles 



