RECLAMATION OF MARSH LANDS. 607 
erally the ease along the shores of large rivers and estuaries, where the silt from tho 
river-bed is continually being washed up against the bank, and during high tides car- 
ried over and deposited on the surface of the marsh along the river-banks, forming a 
compact soil, which, when used in the construction of a bank and dried, becomes hard, 
durable, and water-tight—the three most important requirements for an embankment. 
The fitness of these marsh soils for embankments has been tested, and where used 
not the least trouble has been experienced with them either by a settlement or breach, 
but the shape of the bank has been preserved unchanged after severe winters and 
heavy rain storms. 
When banks are erected to exclude water, they must be made perfectly impermeable 
to that element. The least leakage is but the forerunner of “a burst,” unless quickly 
attended to. These leaks are frequently caused by the imperfect construction of the 
bank itself, where the material is not packed close, or some of the joints between the 
sods of soil have not been thoroughly closed by the workmen. Another cause may be 
the shrinkage of the material when drying in the bank, joints that were close while 
the moisture swelled the material of the bank being opened by the shrinkage of the 
soil, and admitting tiny streams, which soon become serious leaks, and finally the cause 
of the destruction of the bank. Of the two causes, either may be guarded against by 
proper care in constructing the bank. 
There is still another cause of leakage and the failure of a bank—the penetration of 
the bank by musk-rats and other boring animals, whose attacks must be steadily resisted 
by constant vigilance and the adoption of some plan of construction which will defeat 
their operations. Several attempts which have been made at reclamation in this 
country owe their failure to the musk-rats. These animals are not to be despised as 
enemies to marsh reelamation. As workers they are unrivaled in perseverance, for 
. they will return again and again to the attack on the same point of an embankment, 
until they succeed in boring it to their satisfaction, or are killed by a lucky shot. On 
the Newark meadows, New Jersey, they were defeated eifectually by means of theiron 
plate inserted in the embankment, and covering the space between the range of high 
and low water. The rats penetrated the bank in many places, but were stopped by the 
pies and they either gave up their excavation or cut their way over the plate at a 
evel above that of high water, and the consequent injury to the bank was slight and 
easily repaired. A core composed of aless expensive material than iron would answer 
the same purposes, and a well-constructed dike core of wood, hemlock for instance, 
will probably be found fully equal to all requirements. There are conditions, how- 
ever, under which the iron core might be preferable. 
To accomplish the second important condition, the collection and removal of all 
waters lying stagnant or otherwise, and having their source of supply within the lim- 
its of the marsh, a series of main and intermediate ditches or drains must be cut 
through the marsh, for the collection and conveyance of these waters to some point 
or points on the line of the main embankments from which it can be forced out by 
pumps, or drained out by sluices. 
In the case of tide marshes, where the range of the tide brings the low-water level 
sufficiently below that cf the marsh surface to admit of the drainage of the soil to a 
proper depth, and a fair outfall for the water collected in the ditches, a number of 
well-placed and properly-constructed sluice-gates will assist: considerably in draining 
the land, as the volume of water drained into the river or bay will be in proportion to 
the fall and capacity of the sluice to discharge it. Although many advantages are 
derived from the use of sluices on marsh lands, they are not to be compared in 
efficiency with a well-construeted pump, worked by steam-power. No matter how 
well constructed a sluice may be, or of what material, there is always a weakness 
about it and a liability to accident that must impress itself upon the observer. The 
connection made between the embankment and the wood-work or masonry of a sluice 
is, in nine cases out of ten, the site of numerous leaks, which are continuously enlarging 
and are the more dangerous on account of their apparently trifling character. The 
material of a sluice may be iron; it corrodes and gets easily clogged by slight ob- 
structions, such as small branches of trees or tufts of grass. If made of wood, it is 
liable to rot away under water, and be unexpectedly destroyed by a violent storm or 
other cause. The stone-work setting of a sluice, on account of the alternate wetting 
and drying process that goes on, particularly during the winter frests, will work out 
all the mortar or cement from the joints, and the whole sluice is liable to be under- 
mined by the action of the current passing through the sluice twice in every twenty- 
four hours. If the sluice is self-acting, it is a source of danger, as it is liable to be 
obstructed by floating wood, grass, weeds, &c., and is certain to be frozen up in winter 
time, and in case it should be so prevented from working properly, the sluice being 
set to low water, the obstruction to the free flow of the water or to the closing of the 
gate against the rising tide will not be discovered until, in the latter case, the tide 
begins to flow in through the sluice, when the obstruction is placed out of reach. 
In this way considerable damage may be done to young creps by an overflow of salt 
or brackish water. If the sluice.is worked by hand, it is equally dangerous, as 
