Los Angeles daily herald., 1888-08-20


to be heard in it should always accompany his
screed with his full name. not necessarily for
publication but as guarantee Of good faith
The OutfaIl sewer.
EDITORS HERALD-In the HERALD of
the Sd inst. there is letter signed "Tax-
payer" in which the writer has endeav
ored, by making assertions not founded
on facts, to controvert some statements
made by me in letter in your issue of
the 30th ult., relative to the defective de-
sign of the lately proposed outfall sewer.
In this letter I quoted we'll known au-
thorities in engineering to prove that the
maximum safe velocity allowed in a
sewer built of good, hard bricks is five
feet per second. With reference to this
Taxpayer" writes "Frautwine and the
other authorities cited above refer to the
ordinary building brick" now proceed
to prove that the authorities quoted by
me did not refer to the ordinary building
brick, but to specially selected, sound,
we'll burned brick. Sanitary engineering
by Baldwin Latham is work recognized
as an authority on sewer construction in
England and America. Latham states !:
"The selection of bricks for the con-
struction of sewers is matter that re-
quires a considerable degree of attention
at the hands of the engineers.
For sewer works specially sound bricks
are required, as such brick are subjected
to variety of forces, all tending to their
destruction. The best bricks
for the construction of sewers, more espe.
cially for those parts of the sewer liable
to wear and tear from the erosion of the
matter, and the materials transported
over the bed of the sewer are the Blue
Staffordshire, or the Buckley bricks from
North Wales" The specifications for
brick sewers in Europe, and in every city
in the United States, where sewers are
properly constructed, contain clauses to
the effect that bricks for the inverts are
to be specially selected, hard bricks,
sound and we'll burned. give few in
stances. In the specifications for sewer
work at Washington, D. c., we find un-
der the heading, "Brick- work )" "the best
quality of whole, new bricks, burned
hard entirely through, free from injuri-
GUS cracks, with true faces, and with a
crushing strength of not less than 5000
pounds per square inch, will be used.''
When Taxpayers patent continuous kiln
turns out bricks capable of bearing this
test, then, indeed, such bricks may with
confidence be used in the construction oi
sewers, having velocity of less than five
feet per second.
In Philadelphia, for high velocities ap-
preaching ten feet per second, that is,
for instance, such a velocity as the sewer
advocated by Taxpayer has, granite or
hard trap invert blocks are nsed. In
the reports and works on sewer construc-
ton, written by American engineers,
special stress is laid on the selection of
brick for sewer construction. give quo
tations from the reports Of two well-known
authorities on sewerage. In Rudolph
Herring's report to the National Board of
Health on the Sewer Systems of Europe,
he states:
"The hardest materials were built into
the invert to prevent securing, as the
blue brick in England"
Mr.. Herbert Shedd, in mis- report on
the sewerage Of Providence, r. L., states:
"The grinding action of sand and
other solid matter flowing with water
over the inverts of sewers wears them
away more or less rapidly. To prevent
such action as far as possible, the hardest
and toughest bricks should be used in
that part of the sewer.",,
have quoted sufficiently to prove that
Taxpayer" made misleading state
ment when he asserted that the autho-
rites I quoted referred to ordinary
building bricks for the construction Of
sewers. 1t will be seen that, on the
contrary, they lay stress on the selection
Of good bricks for the inverts OF sewers.
In the Eastern States engineers do not
usually adopt greater velocity in
sewers than five feet per second, as they
do not consider that brick can with
safety bear greater velocity. "Tax-
payer" is not content to make equally
good brick to those used in Eastern
cities. In effect he states that bricks in
ferior to those made in the East are to
be manufactured for the outfall sewer.
He states that bricks for this sewer are
to be burned in patent continuous kiln,
and he further states that:
"Bricks specially burned under this
process could resist the abrasion of the
debris in sewer when the velocity of
the water would be six or seven feet per
second" As all the authorities on
sewer construction state that velocity
Of seven feet per second is destructive to
brick sewer prefer to take their opin-
ion before the opinion of Taxpayer. An
advocate or witness who endeavors to
prove too much Injuries the cause which
he advocates. Taxpayer" is in this posi-
ton. He attempts to prove too much.
Taxpayer" gives quotation from my
letter in which state, eve must accept
facts" Now in Taxpayers" letter do
not find fact to accept. His letter is
made up of statements not founded on
facts and on promises not likely to be
fulfilled HYDRAULIC ENGINEER.
August II, 1888.
NUNDV nav nAIH. nn n.nrnO