DRAINING. 
pose at A). But if the texture of every part 
of this stratum was equally strong, the water 
would squeeze through many small crannies, 
and would ooze out in numberless places, 
as between A and K, so as to occasion that 
hind of wetness that is known by the name of 
a spouting clayey soil. 
I he cure, in this case, is much more easily 
effected than in any of the former ; for if a 
ditch of a considerable size is opened, as at 
A, towards the lowermost side of the spouting 
ground, so deep as to penetrate through the 
upper stratum of clay, and reach to the gra- 
vel, the water will rise up through it at first 
"ilh very great violence, but will gradu- 
ally decrease as the pressure from tire water 
behind is diminished ; and when the whole 
of the water accumulated in this subterrane- 
ous reservoir is runoff, there being no longer 
any pressure upon the clay above it, the 
whole soon becomes as dry as could be de- 
sired, and continues so ever afterwards, if the 
ditch is always kept open. 
It will hardly be necessary in this place to 
put the farmer upon his guard to be particu- 
larly careful in his observations, that he mav 
distinguish between the wetness which is pro- 
duced from this cause*, and that which pro- 
ceeds from the cause before-mentioned; be- 
cause the treatment that would cure the one 
would be of no use at all to the other. The 
attentive observer likewise will readily per- 
ceive, that if any field that is wet from this 
cause admits of being ploughed, it will be in 
equal danger of being hurt by being raised 
into high ridges with the other kind of damp 
ground before-mentioned. For as the depth 
of earth above the reservoir would be smaller 
in the deep furrows than any where else, there 
would be less resistance to the water in that 
place, so that it would rise there in greater 
abundance. And if, in this case, a farmer 
should dig a drain in each furrow, as a con- 
siderable quantity of water would rise into 
them, in some cases, the ground might be 
improved or even quite drained by it, espe- 
cially if they should have accidentally reached 
the gravel in any one place, although at an 
expence much greater than was necessary. 
We take notice of this circumstance, in some 
measure to prevent the prejudice that some 
inattentive observers might entertain -against 
what was said before of this method of drain- 
ing, from their having accidentally seen some 
fields that may have been bettered by it. 
Bogs are only a variety of this last-men- 
tioned kind of wet ground, and therefore 
ought in general to be drained after the same 
manner with them. Clay is a substance that 
strongly resists the entrance of water into it ; 
but when it is long drenched with it, it is, in 
process of time, in some measure dissolved 
by it, loses its firmness of texture and consist- 
ence, and becomes a sort of semifluid mass, 
which is called a bog; and as these are some- 
times covered with a strong scurf of a parti- 
cular kind of grass, with very matted roots, 
which is strong enough to bear a small weight 
without breaking, .although it yields very 
much, it is in these circumstances called a 
shake-bog. But whatever is the nature of 
the bog, it is invariably occasioned by water 
being forced up through a bed of clay, as 
just. now described, and dissolving or soften- 
ing a part of it: we say only a part, because 
whatever may be the depth of the bog or 
s waggle, it generally has a partition of solid i 
clay between it and the reservoir of water 
under it, whence it originally proceeds: for 
it this was not the case, and the quantity of 
water was considerable, it would meet with 
no sufficient resistance from the bog, and 
would issue through it with violence, and 
carry the whole semifluid mass along with 
it. But this would more inevitably be the 
case if there was a crust at the bottom of the 
bog, and if that crust should ever be broken, 
especially if the quantity of water under it 
was very considerable : and as it is probable 
that, in many cases of this sort, the water 
slowly dissolves more and more of this under- 
crust, we make no doubt that, in the re- 
volution of . many ages, a great many erup- 
tions of this kind may have happened, al- 
though the)' may not have been deemed of 
importance enough to have the history of 
them transmitted to posterity. Of this kind, 
although formed of a different substance, we 
consider the flow of the Bolway-moss in Nor- 
thumberland to have been; which, upon the 
Ibth ot November 1771, burst its former 
boundaries, and poured forth a prodigious 
stream of semifluid matter, which in a short 
time covered- several hundred acres of very 
hue arable ground. Nor will any one 
who is acquainted with the nature of moss, 
vvho knows its resemblance to clay in its qua- 
lity of absorbing and retaining water, and its 
very easy ditfusibility in it, be surprised at j 
this ; as, from all these properties, it is much | 
better adapted for forming an extensive bog, ! 
and therefore in greater danger of producing - 
an extensive devastation by an eruption of 
the water into it, than those that are formed ■ 
of any kind of clay whatever. 
ii the bog or swampy ground is upon a 
declivity, the ditch ought to be carried across 
the. held about the place where the lowest 
springs arise. But it the surface of the ground 
is level, or nearly so, as between A and B, 
tig. 60. and the springs break out in several 
places, qqqqqq, so as to form soft quagmires 
interspersed through the whole of the field, 
it will be of little consequence in what part 
the drain is opened ; for if it is dug up so 
deep as to allow (he water to rise in it with 
freedom, it will issue through that opening 
and the field will be left perfectly dry. 
But as it may frequently happen that the 
stratum of gravel is at a considerable depth 
beneath the surface of the earth, and as 
it may be sometimes even below the level 
of the .place into which the drain must be 
emptied, it might sometimes be extremely 
diflicult to make a ditch so deep as to reach 
tlie bed of sand or graveL But it is lucky 
for us that this is not absolutely necessary in 
the present case ; as a drain of two or three 
feet deep, as at D, will be equally effectual 
with one that should go to the gravel. All 
that is necessary in this case is, to sink pits 
(B) in the course ot the drain, at a moderate 
distance from one another, which go so deep 
as to reach the gravel ; for as the water there 
meets with no resistance, it readily flows out 
at these openings, and is carried off by the 
drain without being forced up through the 
earth, so that the ground is left entirely dry 
ever after. 
Let it be carefully noted, that if you at- 
tempt to make your pit in one of these soft 
quaggy places where the water is found in 
great abundance, you will meet with very 
great difficulty in forming it; for as the sub- 
4 
! stance of which it is composed is soft, it will 
always flow into the hole as fast as )ou dig 
it ; on which account we should advise not to 
attempt to make tlie pit in the swaggle or 
shake-bog, but as near it in tlie solid^earth 
as you conveniently can. However, if it ii 
pretty firm, and of no great extent, it is 
sometimes practicable to make a pit in the 
soft bog at tlie driest time of the year. This 
soft quaggy ground has seldom been found 
above tliree or four feet deep, below which 
there is always found a stratum of hard tough 
clay, usually mixed with stones, and so firm 
that nothing but a mattock or pick-axe could 
penetrate it ; and as this is comparatively so 
much drier than the ground above it, aii in- 
experienced operator is very apt to imagine 
that this is the bottom that he is in searcl? of. 
In digging through this stratum, you will fre- 
quently meet with small springs oozing out 
in all du ections , some ot them that ini°ht 
fill the tube of a small quill, and others ''’so 
small as to be scarcely perceptible: but 
without regarding these, you must continue 
to dig on without interm ssion till you come 
to the main body of the reservoir, if we may 
so call it, that is contained in the rock, gra- 
vel, or sand, which you will generally find 
from two to four feet below the bottom of the 
swaggle, and which you will be In no danger 
ot mistaking when you come to it; for if 
there has been no opening made before that 
in the field, as soon as you break the crust 
immediately above the gravel or rock, the 
water bursts forth like a torrent, and on some 
occasions rises like a jet-d’ev.u to a consider- 
able height above the bottom Of the ditch, 
and continues to flow off with great impetu- 
osity for some time, till the pent-up water 
being drained off, the violent boiling up be- 
gins to subside, and the strength of the cur- 
rent to abate ; and in a short time it flows 
gently' out like an ordinary spring: allow- 
ing it to remain in this state, the quasrgy 
earth begins to subside, and gradually ~be'- \ 
comes tinner and firmer every day ; so that, ; 
in the space of a few months, those bogs 1 
which were formerly so soft as hardly to sup- ! 
port tlie weight of a small dog, become so 
firm, that oxen and horses may tread upon 
them without any danger of sinking, at the 
very wettest season of the year. We have 
known a field of this nature' that, by having 
only one such pit as has now been described : 
opened in it, was entirely drained to the dis- 
tance ot above a hundred yards around it in 
every direction. But as it is possible that 
the stratum in which the water runs may be : 
in some places interrupted, it will be in ge- : 
neral expedient to make several of these 
pits, it the field is of great extent, always car- 
rying the drain forward through the 'lower- 
most part of the field, or as near tlie quag as : 
you conveniently can, and sinking a pit wlier- ] 
ever you may judge it will be most neces- 
sary. But if the stratum of gravel is not in- i 
terrupted, there will be no violent burst of 
water at opening any of these after the first. 
I o keep these wells from closing up after 
they are made, it is always expedient to (ill 
them up with small stones' immediately after 
they are made, which ought to rise to the 
height of tlie bottom of the drain. 
It the whole field that is to be drained con- 
sists of one extensive bog, it will require a 
long time. before the whole work can be en- 
tirely finished, as it will be impossible to 
