ox DRAINING. 85 



infested by this substance, wliich manifested itself in masses 

 of red deposit at the mouths of the drains, and on ditch 

 banks. Althong-h Mr. Parkes was not aware of there being- 

 much experience in favour of small pipes in such soils, he 

 retained his confidence in pipes as preferable to all other 

 conduits, from the compression of the run of water into the 

 smallest required volume, and therefore as more likely to 

 prevent deposits from occurring' or accumulating- than larg-er 

 conduits. He was acquainted with a solitary case in which 

 pipes of an inch bore had been used, and continued to act 

 well for several years without obstruction in a bog-gy soil 

 charged with iron, thoug-h the ditches into which the pipes, 

 always running- fiill bore, discharg-ed their water, require 

 clearing- once or twice a year to keep them open. To in- 

 crease the efficiency of the small pipe, he proposed laying- 

 them with collars, which would fiu-ther help to cover and 

 diminish the size of the crevice between each pair of pipes, 

 and close it against the entrance of solid matter. After 

 devoting- a week to the examin-ation of the old drains, he 

 found many of them stopped up with a mixture of earth 

 and iron deposit : some of these drains were composed of the 

 common horse-shoe tiles, laid without soles, and others with 

 soles. 



The drains throug-h which water was continually running- 

 were chiefly open, having- g-reat quantities of the deposit at 

 their mouths, and one drain formed of six-inch pipes, con- 

 veying- much water, exhibited the iron copiously as a preci- 

 pitate when the line was broken and a pipe removed, which' 

 exposed the water to the atmosphere ; cess-pools communi- 

 cating- with the atmosphere at top, and into which some 

 drains entered, were also lined with deposit. I examined, he 

 adds, several drains serving- as mains, and particularly at their 

 point of junction with minor drains, and I found one of 

 these drains about six feet in depth, and very well con- 

 structed, to be nearly closed with what appeared to be a 

 pure specimen of the deposit, having- the red colour of pe- 

 roxide of iron, and of a pasty texture. This particular mass 

 of deposit had occurred at the jimction of a branch with 

 the main, about thirty or fort}'" yards fi-om the hig-her end 

 or orig'in of each drain, and where the run of water would 

 necessarily be g-reatly less than as it approached the outfall j 

 and I have found at Drayton INIanor, and many other places 

 where ferruginous matter abounds, that stoppage from its 

 deposit is much more frequent towards the higher than 



