Geology of the Keythorpe Estate. 



101 



adapted than pipes or tiles of any kind. In order to make a 

 fair comparison, it is necessary to compare like things with like, 

 collared pipes with collared pipes, tiles and soles with tiles and 

 soles, and so forth. Lord Berners uses pipes of l-^- and 2 inches 

 diameter for the drains, and 3-inch pipes for the sub-mains, both 

 without collars. I should have preferred collared pipes ; but his 

 Lordship's argument in favour of those which he uses is 

 unanswerable : " I find them succeed in this soil without collars, 

 and they are cheaper." For the junctions, branch pipes are 

 made, the branches joining the main pipe at 

 various angles. His Lordship informs me that 

 he finds them useful for forming, not only hori- 

 zontal, but vertical junctions, when the parallel drains are shal- 

 lower than the submains into which they discharge. 



On entering on the comparison proposed, it should be pre- 

 mised that on a soil so tenacious, the deepest drainers, on the 

 principle of equidistant drains laid with the fall of the surface, 

 would not place their drains at wider intervals than 8 and 10 

 yards. I believe few would exceed the smaller interval. At 

 intervals of 8 yards there would be 110 statute perches (of 16^ 

 feet) to the acre. The proportion of submains depends on the 

 form of the field and the contours of the surface. Allowing 

 that the drains shall not exceed 10 chains, or 220 yards, without 

 discharging into a submain, there would be, under the most 

 favourable conditions of form and contour, 4 perches of submain ; 

 making a total of 1 14 perches of drains and submains. At in- 

 tervals of 10 yards there would be 88 perches of drain and 4 

 perches of submain, as in the last case ; total, 92 perches. Let 

 us now compare this with the Keythorpe system. Lord Berners 

 has a map, on which the drains of each field are laid down, and 

 on which is recorded the amount paid for labour in draining it. 

 Out of four cases given me by his Lordship at hazard from this 

 map I select the highest and the lowest ; the highest is Over 

 Hammer. Its area is 7 acres, drains generally 3i feet deep, 

 with some 6 feet deep. The customary measure for draining in 

 this part of Leicestershire is very anomalous — a linear acre of 24 

 yards. To avoid confusion I reduce the quantities thus stated to 

 yards, and find that there are 3t feet drains 2436 yards 



6 feet drains 204 „ 



Total 2640 



This is equal to 480 perches ; and as the field contains 7 acres, 

 there are 68^, or say 69 statute perches of drains to the acre. 

 This includes submains as well as parallel drains. 



The lowest case is No. 39, area "dh acres ; length of parallels 



