The Lee County journal. (Leesburg, Ga.) 1904-19??, 1906-03-23
aking the Sea Build ........
80. Its Own Prison Walls

the lOw-water mark has been driven
back from 200 feet to 500 feet, at
Blackpool, Bray, Sherngham. Beeston,
Mariakerke and Middleklrk (Cstend),
Deal and elsewhere.
1t is evident that one of the chief
recommendation of the system will be
its low cost, since, as the average
height of the groynes above beach lev
Ell is not more than two feet. they can
be made of very light construction, so
much so that a length of about 600 feet
has been constructed in a single tide.
Up till now they have been built OF
wood. and in some places the teredO
has extensively attacked them, so that
in order to combat it's ravages it is
now proposed to construct them of re-
inforced concrete after the design OF
DR.. ]. S. Owens. In order to reap the
utmost benefit from grooming. it seems
advisable that the groynes should be
carried out as far as possible beyond
low-water level, so as to intercept to
the greatest extent the off-shore cur
rents, although every coastline will be
law unto itself.
1t is re1-arkable how much solid
matter the sea will carry in suspension
and how much also it may be made to
deposit in this manner. though it must
be understood that shingle and quite
large pebbles ere just as readily ar
rested as is fine sand. Not the least
advantage due to the use of groynes is
their action in causing an accumulation
at the base Of sea walls from which
they run.
Formerly all groynes were placed
at right angles to the beach, and the
Case system has attained to success by
adhering to this plan there is, how
ever. a movement now in favor of plac-
ing them at an acute angle under GER
tain circumstances. 1t is beginning to
be recognized that to secure the best
advantages, every local condition-the
direction and play of the shore cur
rents, the prevailing winds, the slopes
of the coast, the rise of the tide, the
its constituents, its position with re-
gard to neighboring coast and the set
of the tides-must be properly taken
into consideration.
Excellent as low groynes have
proved to be. they have failed in GER
tain places-St. Margaret's Bay, Kent,
and Glenbeigh, County Kerry, may be.
cited-and it is probable that this is in
some measure due to an incomplete APP
probation of every factor Anyhow,
it seems highly probable that given
favorable conditions, acute-angle
grOynes may very we'll be the best, and
in one instance, at least-at Lowe
stoft, where the low water mark has
been driven back some $50 feet-they
have proved to be so. The erection of
these groynes was due to Lieutenant J..
o. Williams, r. N, who is consistent
in advocating the theory that acute
angled groynes are generally prefer
able to those at right-angIes.
Practically speaking, Lieutenant
Williams takes advantage of the Case
system of low groynes, but he puts
them at an acute instead Of a right
angle, and in places throws out spur
groynes from them Certainly success
has attended his first experiments, but
an equal or even greater success has
been accomplished with the Case right
angled groynes in other places. leading
to the belief that there may be a best
angle, varying from a right angle down
to a very acute angle, for every coast,
and that the conclusion reached by
some experts that there is no advan-
tage in departing from the former is
not justified by facts.
1t is quite probable that the theory,
advanced by Mr.. R. G. Allanson-W inn,
of grOynes partly at right angles Qrom
low-water level up to mean-water
leveD, and then curving into the land
in an elliptical curve, would be found
very advantageous in places, combin-
ing as it does both the Case and the
williams methods. A compromise"
groyne of this description, with pos
sibly one or two spur grOynes, might
very well prove exactly what is want
ed under easily imagined circum-
stances. 1t can, however, be accepted
that low grooming of whatever form
has so far proved the best agent (and,
in most cases, a thoroughly reliable
one) for inducing accretion, and so
stopping or retarding corroslon.-Lon'
don Times.