l resist their force. Ordinarily,
the best, because the cheapest, material of which these embankments can be
made, is the soil of the marsh itself. This is rarely,--almost never,--a
pure peat, such as is found in upland swamps; it contains a large
proportion of sand, blue clay, muscle mud, or other earthy deposits, which
give it great weight and tenacity, and render it excellent for forming the
body of the dyke. On lands which are overflowed to a considerable extent
at each high tide, (twice a day,) it will be necessary to adopt more
expensive, and more effective measures, but on ordinary salt meadows,
which are deeply covered only at the spring tides, (occurring every
month,) the following plan will be found practical and economical.

_Locating the line of the embankment_ far enough back from the edge of the
meadow to leave an ample flat outside of it to break the force of the
waves, if on the open coast, or to resist the inroads of the current if on
the bank of an estuary or a river,--say from ten to one hundred yards,
according to the danger of encroachment,--set a row of stakes parallel to
the general direction of the shore, to mark the outside line of the base
of the dyke. Stake out the inside line at such distance as will give a
pitch or inclination to the slopes of one and a half to one on the
outside, and of one to one on the inside, and will allow the necessary
width at the top, which should be at least two feet higher than the level
of the highest tide that is known ever to have occurred at that place. The
width of the top should never be less than four feet, and in exposed
localities it should be more. If a road will be needed around the land, it
is best, if a heavy dyke is required, to make it wide enough to answer
this purpose, with still wider places, at intervals, to allow vehicles to
turn or to pass each other. Ordinarily, however, especially if there be a
good stretch of flat meadow in front, the top of the dyke need not be more
than four feet wide. Supposing such a dyke to be contemplated where the
water has been known to rise two feet above the level of the meadows,
requiring an embankment four feet high, it will be necessary to allow for
the base a width of fourteen feet;--four feet for the width of the top, six
feet for the reach of the front slope, (1-1/2 to 1,) and four feet for the
reach of the back slope, (1 to 1.)

Having staked out two parallel lines, fourteen feet apart, and erected, at
inter