RECLAMATION OF MARSH LANDS. 609 
mountains. Tracts of peat bog in various parts of Ireland and England, where the 
surface is soft and shaking, are as high as eight feet above the level of the adjoining 
dry and arable land, and the water of these bogs rarely interferes with the dry land in 
the immediate vicinity, as it is held by the soil of the peat bog by capillary attraction 
stronger than gravity itself, which latter force asserts itself wherever the particles of 
soil are incapable of losing their identity by being blended in a general mass. The 
action of this capillary force on the water in the subsoil and the result in favor of 
vegetation has already been stated in this article and needs no further explanation. 
When an outfall is secured, and aregular system of main drains established, the 
freeing of the excess of moisture for the purposes of cultivation is accomplished by the 
smaller drains, which intersect the areas not immediately affected by the main drains. 
The size and capacity of these sub-drains will of course be suited to the area affected 
and the degree of humidity of the soil. In some parts of the same marsh tract the soil 
differs so considerably in its nature as to necessitate a variation in the plan of drainage. 
The proximity of high lands, woods, springs, er other causes of excessive moisture in 
the soil, must be taken into consideration and provision be made accordingly, but the 
general principles by which the detail drainage of the land is affected must be observed. 
A general inclination or fall of all minor drains to a main drain is as necessary as 
the fall of the main drain to the outlet, sluice-way, or pumping station. Where tile 
drains are laid, a fall of one foot in two hundred is sufficient to carry off the water, but 
as there are many cases in which drain pipes cannot be employed, it is desirable that, 
while affecting as much ground as possible by a drain, every advantage should be taken 
of a good fall on the line of each drain, whether a main or an intermediate drain. Va- 
rious plans for intermediate drains have beensuggested and adopted from time to time. 
Among them may be mentioned one that is formed by a simple trench, cut with a 
shoulder to support a covering sod, laid grass down, and covered to the surface with 
the excavated soil. This drain does not last long, but is an economical form. Another 
kind of drain is made by leaning the flat tiles bridgewise against one another on 
top, the apex of the triangle so formed being covered with a thick sod, and the 
remaining part of the trench filled with broken stone and excavated soil. The tile- 
and-shoe drain has been used extensively in many parts of England. It is a horse-shoe 
tile, resting on a flat tile, thereby forming a kind of arched drain, from one to four 
inches in diameter. This style of drainis not now used so much as the simple circular 
drain pipes, with collared joints, where such a precaution is necessary to preserve the 
efficiency of the drain. These drain pipes are of burnt clay, about fourteen inches in 
length and from one to fourteen inches in diameter. ; 
In very humid soils it is necessary to provide a sufficient number of drains to carry 
off the water after heavy rains as fast asit soaks into the greund. Experiment will soon 
establish the proper positions and distances apart for these drains. As it is necessary 
to the productiveness of a soil that the warm rain-water should penetrate below the 
line of vegetation, the drains should be laid at such a depth as to be clear of the plow 
and spade, and the frost and the tap-roois of larger plants. As soils are very rarely 
broken below eighteen inches from the surface, and roots are known to reach down as 
far as the soil is rich, while the frost penetrates to an average depth of three feet, 
it would be safe in districts affected by frost to lay drains four feet under the sur- 
face, and in warmer climates at a depth of one foot below the line of cultivation. 
With a suitable connection between the main and the drains, no soil, no matter how 
wet it may be, can failto be reduced to a condition fit for cultivation. 
As localities differ widely in their physical features, and various circumstances com- 
pel special treatment in almost every case, it is not practicable to designate, beyond 
the general principles that should govern the construction and arrangement of reclam- 
ation works, any form of embankment, drain, sluice, or pump to be adhered to under 
all cireumstances. Locality, prevailing winds, climate, range of tide, strength and ve- 
locity of local currents, the nature of the soil and vegetation, all combine to alter the 
character of the works, and a common standard would be impossible. It may be said 
of all these that locality is the one on which all the others depend for their importance. 
We find as we traverse the Atlantic coast of this continent a great many varieties of 
soil in the marshes. This is owing to the different kinds of vegetation produced on 
these marshes, or which composed their soil originally, and the rapidity of decomposi- 
tion of this vegetable material in the soil. With locality, climate varies considerably, 
and climate regulates the character and growth of plants, their development, their 
time of maturity and of decay. A natural result of all this influence must be that in locali- 
ties possessing warm climates the vegetation is more varied, more luxuriant, and con- 
sequently enters more largely into the composition of the soil than in places where the 
climate is less favorable for the development of vegetation. The rapid growth and 
quick succession of crops must tend to a large annual deposit of vegetable matter on 
the surface, which, before it becomes thoroughly decayed, is itself a soil, from which 
other plants spring, and the deposit becoming in this way more rapid than the decay 
which should convert it into vegetable mold, a soil is formed many degrees Tess dense 
39 A 
