17 The drains, which are removed a little to one side of the lines of
stakes, may be turned toward the basin from a distance of 3 or 4
feet.

18 The foot of the measuring rod should be shod with iron to prevent
its being worn to less than the proper length.

19 "Talpa, or the Chronicles of a Clay Farm."

20 When chips of tile, or similar matters, are used to cover openings
in the tile-work, it is well to cover them at once with a mortar
made of wet clay, which will keep them in place until the ditches
are filled.

21 Surely such soil ought not to require thorough draining; where men
can go so easily, water ought to find its way alone.

22 The land shown in Fig. 21, is especially irregular, and, for the
purpose of illustrating the principles upon which the work should be
done, an effort has been made to make the work as complete as
possible in all particulars. In actual work on a field similar to
that, it would not probably be good economy to make all the drains
laid in the plan, but as deviations from the plan would depend on
conditions which cannot well be shown on such a small scale, they
are disregarded, and the system of drains is made as it would be if
it were all plain sailing.

23 Klippart's Land Drainage.

24 Klippart's Land Drainage.

25 Drainage des Terres Arables, Paris, 1856.

26 The ends of the work, while the operations are suspended during
spring tides, will need an extra protection of sods, but that lying
out of reach of the eddies that will be formed by the receding water
will not be materially affected.

27 The latest invention of this sort, is that of a series of cast iron
plates, set on edge, riveted together, and driven in to such a depth
as to reach from the top of the dyke to a point below low-water
mark. The best that can be said of this plan is, that its adoption
would do no harm. Unless the plates are driven deeply into the clay
underlying the permeable soil, (and this is sometimes very deep,)
they would not prevent the slight infiltration of water which could
pass under them as well as through any other part of the soil, and
unless the iron were very thick, the corrosive action of salt water
would soon so honeycomb it that the borers would easily penetrate
it; but the great objection t