264 
On Draining. 
in certain very fluid and fine media, but when a drain thus formed 
is carefully laid and filled in, my belief is that it will resist the 
entrance of all matter, except water. To use the apt expression of 
one of my workmen, " nothing else can get in when the water sighs 
into the drain so quietly." 
Another cause of obstruction to drains is the entrance into them 
of the roots of trees and plants. Of the former several cases have 
been reported to me as having occurred, and probably no species 
of close under drain, yet constructed, can be considered to be 
absolutely safe from the roots, if laid within the range of their 
travels : and the great distance from the parent tree to which roots 
will travel in search of food, is well known to every agriculturist. 
It would be venturing too much to say that a root will not enter 
drains by any, even the smallest conceivable, crevice or pore, which 
will admit water ; for cases have been mentioned to me almost 
justifying the belief that roots have insinuated themselves through 
Roman cement. They seem, however, to be very capricious and 
choice in their attacks, for I have seen drains which have conti- 
nued perfectly free in their action for years, adjoining fences and 
plantations, Avhilst a drain, at a greater distance, has been choked 
by roots. In the two or three cases observed by myself, I have 
found that a single thread-like root alone has entered, and then 
worked its way up against the run of the water, increasing into a 
hairy mass, something like the brush of a fox, and growing in length 
sometimes to several yards, until it closes the drain as completely 
as if it were stopped full of clay. In situations where drains 
must be laid near to trees, I would advise the keeping as far off 
as circumstances permit, and the providing each row of pipes, 
if joining a main, with a cess-pool at their junction, in order that 
the discharge may be visible and examined occasionally, which 
would soon detect a stoppage if it occurred. But it will be wise 
in all cases, if people will have hedge-row trees, that the drainer 
so plan his operations as to keep as wide of them and fences as 
possible — but, better still, to get trees felled wherever they occa- 
sion a feeling of doubt as to their affecting the permanency of the 
drainage, or cause it, in respect of the direction or depth of the 
drains, to be other than complete. If trees, .as in parks, are in 
the way of drains, I advise the sheathing of the pipes on approach- 
ing within 20 yards, and I frequently diverge from the line and 
pass round the tree to regain the true line of drainage. 
VVith stoppages from the roots of plants I have only very recently 
become acquainted, but this evil does occur, though fortunately it 
is of very rare occurrence. The first case known to me took place 
this year in a field on an estate of Mr. W. Wolryche Whitmore, 
at Lebotwood, in Shropshire. A tenant of his laid a pipe-drain 
last March in a boggy piece of ground very wet and spongy, which 
