Evening star. [volume] (Washington, D.C.) 1854-1972, 1888-11-22
SOUNDING THE LINING.
The Expert Engineers at Work in the
Tunnel
WHAT STAR REPORTER SAW IN THE HOLE
MANY HOLES DRILLED IN THE BRIcK-woRK-
HOW THE SOUNDING Is DONE.


work on the construction Of the aqueduct
tunnel has been suspended since the 9th in
slant, but what on its face looks like work Of
destruction is proceeding very actively six days
week. The brick arch has been pierced in SO
many places that full view Of it would sug-
gest the top OF gigantic pepper-box. num-
Der OF these orifces were made by Lieut.
Townsend in the course Of his investigation,
but these are few when compared with the
number OF those that have made their appear
ance since the board of civil engineers en-
ployed by the joint congressional committee
commenced their examination Of the brick
tube. Above ground the experts are mute as
CLAIMS, and no amount of ingenious inquiry will
extract from any of them such information as
would be OF interest to the public. In the
depths OF the tunnel however they converse
with freedom and comparative safety. They
are alone with their work. The waterless pub
lie knows nothing Of their proceedings. and it
waits with lll-concealed impotence for some
sign. A STAR reporter who thought there Wa
news in the tunnel succeeded in effecting an
entrance thereto, and from afar off he watched
the maneuvers of the Investigators.
LOCATING THE HOLLOW SPACES.
To locate the hollow spaces above the arch
u the first work. and that is being done by an
expert who rendered similar services in the
New York aqueduct tunnel. which was con-
structed in manner startlingly similar to its
fellow in this city. The instrument used by
the '.sounder" is long, steel rod rounded and
larger end the bricks are thumped, and the
acute senses of feeling and hearing settle the
question OF solid construction or otherwise at
that point. If everything is all right the
"sounder" moves on or feet and taps again,
and so he continues. He does not have to go
hOwaVar hQfnro ha otr ,Lac ,&lo
where the packer thought he would save the
contractors little expense. and when one of
these weak spots gives back the tell-tale echo of
the rods ringing sound the ''sounder" marks
the place and proceeds with his tedious labors.
1t Is slow work. The entire tunnel has to be
tested by this one man, and his progress is al
most snail-like. He expects. however to get
there ultimately. Had the sounding" process
not been adopted it would have been necessary
to thorough investigation that the arch be
the other. So far the "sounder" has done
little but mark weak places for the drillers,
and all these places will have to be opened up
The drill and hammer men follow the
''sounder," and they tear out the brick-work at
the points indicated by him. Up to the present
time they have had no lack Of work.
THE ENGINEER EXPERTS.
Behind the drillers come the engineer ex-
perts three in number, and they examine with
VIC closcSt hiHO VI scrutlny tne character OF
the work which has been exposed. They re-
fuse, absolutely, to give any opinion as to the
construction Of the tunnel except to members
of the joint congressional committee, and to
one Of these they did say that the newspaper
reports on the condition of the tunnel were
really far below the mark instead of being. as
was charged at the time, gross exaggerations.
The expert board will leave the city to-
morrow to attend to the business which has
accumulated at their homes. The two Phila-
delphia engineers will, however. make flying
visits to the tunnel once or twice a week to see
how matters are progressing. The board does
not expect it is understood. to have another
full meeting until the middle of December.
At that time they will carefully examine the
whole construction, and about the first of
January expect to make full report to the
committee.
THE EXPERTS REPORT.
The report will not only give detailed
description of the manner in which the tunnel
was lined, but it will also deal at length with
the plan upon which the tunnel was con-
structed. 1t will be either an Endorsement or
condemnation of the engineering ideas
which brought the tunnel into being. Esti-
mates of the cost of repairing the lining will
also be submitted if the board thinks repairing
would be advisable. but it would not surprise
the congressional committee to any considera-
BILE extent if a new scheme to supply the city
with additional water was agreed upon by the
board and submitted in connection with the re-