On tJie Making and Using Tiles for Under-Draining. 355 



proper earth is often incident to woodland soils, and it may some- 

 times be wortli while to plant around the kiln for future fuel. 



12. After many years' experience, trials of many plans, forms, 

 and sizes, and the use of millions of tiles, the forms and 

 dimensions above given have been settled upon as the best, 

 most effectual, and cheapest ; and the prices are found to be such 

 as just to enable steady industrious men to get a rather better 

 living than by common labour, ordinary wages being 12.9. per 

 week ; but it is evident that a certain quantity must be made to 

 pay a foreman or kilnman : sa,y, 200,000 of all sorts of ware. 

 No holes in the tiles are required, becc.use, in the process of 

 draining, the water falls to the sides of the tile, and gets under its 

 edge to the flat or bottom tile : the lowest drop of water is first let 

 off by the aperture ; this makes way for (and attracts) another 

 drop, and so on to the top. The larger tiles are alv/ays sought 

 for by farmers, if young drainers ; but they are only requisite in 

 case of main drains which have a great length of other drains to 

 carry off the water at headlands, Sic. The small tiles answer all 

 ordinary purposes. 



13. Lands in some counties are ploughed up high into broad 

 ridges (an ancient method of drainage), the tile-drains are then 

 placed in the furrows, and the height of the " lands " or ridges 

 reduced by ploughing down gradually. In such cases there is a 

 very general fear of placing the tiles too deep ; and the conse- 

 quence is, that they are often placed so shallow as to be filled by 

 moles or roots, or displaced by tread of horses or cattle in wet 

 times. In furrow-draining stiff lands, the tiles should ultimately 

 lie 30 inches deep, after the lands or ridges have been ploughed 

 down, but not less than 24 inches at first ; and in looser and more 

 open soils, 30 inches at first, and 36 inches at last, i. e., when the 

 ridges are thrown down, are the proper depths on the average, but 

 more in some places, and the nearer they approximate to these 

 depths the more effectual will be the drain ; since the drain not 

 only acts from the bottom to the top, as already mentioned in 

 12, but because vrater in descending seeks the nearest vacuity: 

 the attraction of the escaping drop downwards is in a diagonal 

 line from the bottom of the drain to the top of the land ; thus, in 

 the following diagram, suppose the influence of a deep drain, say 

 36 inches (a), to be in the line he, as far as the point c, say 18 

 feet of surface; now the shallow drain (tZ), say 18 inches deep, 

 can only have an influence in a diagonal line parallel to he to the 

 point e, vvhich will be 9 feet of surface. 



