The herald., 1894-09-30

they did not believe the sitting Of tho
harbor to any great extent wonld resrlt
from continuous break water connected
with the shore.
Ihey differed with the board OF 1891
In this, and think they were in error.
CONFUSING THE DIRECTION OF THE WIND.
Second-The board of 1892 confused
the direction of the wind with that OF
the swell. and calculated protected or
unprotected areas in the two localities
according to wind directions rather than
swell directions. and to the prejudice of
both points, particularly Santa Monica.
In TINS also they differed from tho board
OF 1897, and again think erroneouslv.
Ii requires detailed reference TO nm.
derstand this. In House Elk. Doc. No.
Al. p. Is. of the report of the board of
1892, they compared exposures by using
direction of wind rather than swells.
although they copied statements from
the report of the board of 1891. and
from the statement of Professor George
Davidson, both OF which statements are
emphatic In the opposite direction. (See
Elk. Doc. No. Al, p. Z, lines l3 to 20, and
p. lO4, where Professor Davidson states:
I'm our southeasters the swell of tha
Pacific comes from the southwest.")
EXPERIENCE AT THE NEW WHARF
at Port Los Angeles. since the report OF
the board OF 1892 was made, confirms
the above statement; the very heavy
swells come from southwesterly direc-
tion, moving toward the coast about
north so degrees east magnetic course.
While the direction OF the ordinary
swell is about north 81 degrees east
ms Thaao
careful observations at Port Los Angeles
wharf.
In designating breakwater the loca-
tion should take into consideration both
of these directions and be placed so that
1t would offer the largest amount of pro-
lection.
SERIOUS ERROR OF ENGINEERS.
By using wind, not swell direction.
from the southeast to determine the pro.
tected area behind breakwater at Santa
Monica the board of 1892 erred, greatly
to the prejudice of this harbor, making
the area 22l acres, while from the care
full survey of Port Los Angeles, made in
1898, and basing the calculations on the
length OF the breakwater designed for
Santa Monica by the board of 1891, and
placing it in nine fsthoms I find a pro-
tected area of $50 acres between the AZ
fathom curve and the break water.
ECONOMY OF LOCATION.
Third-While it may possibly be q
matter of no great Importance, as sug.
gested by the board OF 1892, to build in
the most economical location, vet, as the
largest estimate given by the board of
1892 for Santa Monica might be used to
the prejudice of that location and has
been go used, it is necessary to refer to
estimates.
The board OF 1891 made difference in
favor of San Pedro of about 500 600
81 ,s43, 440 at Santa Monica and $4,l26,-
l06 ct San Pedro-whioh seemed to be a
matter of Importance to the chief of
engineers (see Elk. Doc. No. 80, D. p.
Mr.. Hood, In his statement before the
board of 1892 (see Ex. Doc. No. Al, d.
108). showed that this difference was due
to the tact that the former board had
not discovered the bsst and most econ
omioal position for a breakwater in
Santa Monica bay, and that had they
done go there was no doubt of the esti-
mates having been in favor of Port Los
b5r "ialaq.- hut th4, -ast'ras,t ,tnrna ont tp
changing the position OF the breakwater
at San Pedro, bringing considerable
proposed by the former board, and the
adoption, unwisely. think, OF section
of break water only about rs per cent of
that OF the former board. Even aesum-
ing this new section ana new location to
be correct. the estimate ought not to be
used in comparing 1t with the cost of
one at Santa Monica, which was in
deeper water and had much larger
section.
ERROR IN BREAKwATER CONSTRUCTION.
Fourth-The board of 1892 has made
its breakwater the weakest where it
ought to be the strongest, and that is at
the extreme low water line on the sea
side. From that point to extreme high
water, about eight feet, and above that
to the top of the work, about IL feet--18
feet in all-they have designed slope
practically on 1-45 degrees. A slope of
rubblestone breskwster OF this eteepness
could not possibly stand, even while
building the, breakwater. The return
waves of the swells would continually
drag the stones down until they had
formed stable slope OF not less than 2
on /, probably 215 on l, as designed by
the board OF 1891. If this slope which
the 1891 board applied to Santa Monica
had been applied Dy the 1892 board to
San Pedro it would have considerably
exceeded in volume the Port Los An
geles breakwater, and consequently cost
more.
A RECOMMENDATION.
may be psrdoned for recommending
on this or similar work OF the govern
ment a rounded crown of large rough
stone, from one-half to three cubic
yards in dimension, laid with as smooth
surface as possible, with chinks OF
smaller stone and spawls we'll rammed
in. This kind OF work should extend
from extreme low water on the seaside,
up over the crown, down to extreme low
water on the harbor side. The waves
will run up the slope and cover the
crown with little damage to well-laid
surface of this kind.
THE ENGINEERS EXPERIENCE.
In designating the top work. for the
Tampco jetties. when sand for good
concrete, which had been planned, was
not available, | first examined 20 har-
bors in Europe to learn the results OF
various kinds of work. The works at
tho mouth of the Maas, in Holland,
have no concrete whatever, and yet
have for 80 years withstood successfully
the heavy swslls of the North sea with
very small annual expense. They are
built as have recommended above.
At Tampico, 80 far as thoroughly ap-
piled, this plan has worked satisfactori.