Geology of the Keythorpe Estate. 



99 



of the Welland. If we follow its stream downwards for eight 

 or nine miles, we find in its valley still richer ^azing-grounds, 

 consisting of deep warp-drift, holding a position intermediate 

 between the mowing-grounds, which are alluvial, and the poorer 

 soils on the steep sides of the hills bounding the valley, where 

 there is scarcely any warp-drift, and where the strata of lias are 

 either at the surface or near to it. 



On my suggesting that it would be worth trying, whether 

 some of the finer calcareous gravel would not be a beneficial 

 dressing for these clay soils. Lord Berners recollected that some 

 had been spread several years since on some pasture land, and 

 also on part of an arable field consisting of some of the stifFest 

 clay on the estate ; a considerable superiority has been observed 

 on the crops of the arable field so treated. This superiority, 

 however, had hitherto been attributed to a difference in the 

 cultivation and rotation. On the pasture land, which had been 

 covered with this gravel to the depth of 1 or 2 inches, no ambi- 

 guity could arise from those causes ; and there also the improve- 

 ment was very m.anifest. In consequence of the suggestion 

 which I offered having brought these points to remembrance, 

 these experiments will be repeated. Knowing that limestone - 

 gravel forms the staple mineral manure of Ireland, and seeing 

 the result of previous experiments at Keythorpe, I look with 

 great interest, and with the utmost confidence of success, to 

 those now in contemplation. 



The Keythorpe System of Draining. — The peculiarities of the 

 Keythorpe system of draining consist in this — that the parallel 

 drains are not equidistant, and that they cross the line of 

 greatest descent. The usual depth is 3J feet, but some are as 

 deep as 5 and 6 feet. The depth and width of interval are 

 determined by digging trial-holes, in order to ascertain not only 

 the depth at which the bottom water is reached, but the height 

 to which the water rises in the holes, and the distance at which 

 a drain will lay the hole dry. In sinking these holes clay-banks 

 are found with hollows or furrows between them, which are filled 

 with a more porous soil, as represented in the annexed sectional 

 diagram. 



CL a (L a cL a a. 



a a Trial holes. 



6 Clay banks of lias or of boulder-clay. 



c A more porous warp-drift filling furrows between the clay-banks. 



H 2 



