Los Angeles daily herald., 1876-01-01

constant dripping that amounted al
most to to a shower and rendered the
atmosphere damp and disagreeable in
the extreme. The earth excavated
from the head of the tunnel is carried
out on an iron tramway in small
dump cars, and, after being pushed up
the grade to the approach, the descent
is sufficiently steep to run them down
where they are emptied. The man.
ner of
PROSECUTING THE WORK
Is as follows: The advance opening is
made in what is to be the arch of the
tunnel and is called heading.n 1t
extends anywhere from ten to twenty
feet beyond the main opening and
forms space about eight feet high by
fourteen wide. AS fast as the earth is
excavated, heavy temporary braces are
inserted to prevent it from caving in.
Following this gang of workmen is
another who remove the earth from
the body of the tunnel, under the
heading and load it upon the dump
cars to be taken out. Then the car
penters follow and fit in the heavy
timbers that wall the sides and roof,
at the same time removing the tenn
porary braces.
THE LUMBER
used is all Oregon cedar, which is said
to be the most durable wood for the
purpose known. The uprights are
l0xl4 inches and placed three feet
apart ordinarily, though, in places
where:an extra strain is apprehended
not more than nine inches space is
left between them. The arches arsl
formed of heavy three-inch plankS
bolted together to the thickness of the
uprights. They are made in two parts
and brought into the tunnel ready to
be raised and settled into position. On
the outside of this framework there is
complete covering of planks an
timbers called "lagging"-driven in
snugly against the earth. Great care
is taken to leave no open space on the
outside of the structure as it would in
duce cave and perhaps destruction
of human life along with the work.
THE EARTH
through which the tunnel has been
run thus far is mainly blue clay,
sand and gravel. Had it been solid
rock, the work would have been far less
troublesome, less expensive and less
dangerous. AS it is the material is so
compact that it is almost as hard as
rock under the pick, yet dissolves like
snow when brought under the action
of water This renders the work of
excavation difficult and the liability
of cave much more imminent than it
would otherwise be. The earth is
loosened mainly by blasting, giant
powder being employed for the pur-
pose.
INCLINE NO /,
The one nearest to the Northern erd
of the tunnel has been sunk to the lev
ell the roadway-sOme $50 feet. Ithas
been the most troublesome point on
the whole line of work. The shaft is
about II feet square and protected by
a strong frame work. 1t descends at
an angle of about 30 degrees. The
shaft is constantly threatened with an
overflow, and two steam pumps work
ing all the time barely suffice to keep
it dry enough to work in. The Super
intendent proposes to put Cornish
pump in the incline soon, which he
thinks will dispose of all the water
But little headway has been made il
running the line of tunnel at tbs
point. While we were down the wo'k-
men were engaged in putting upthe
first set Of braces, and there wa an
aperture ofscarcely twenty feet sqaare.
INCLINE NO. 2
Had only been sunk some three hun
dred feet and had not reached its des-
tined level, consequently we did not
descend it. Some weeks ago this shaft
was full of water almost to the top,
but it was pumped dry and the work
is progressing in it very satisfactorily
1t was at this point that the boiler ex-
plosion took place some weeks ag9,
injuring several workmen and killing
one or TWO men we believe.
INCLINE NO. 8
Has made the best progress OF all The
shaft to the bed OF the tunnel y 39O
feet deep and the work has beer pros
ecuted Northward $50 feet and to the
South $50 feet. The South endts COM
paratively dry, and but few difficulties
have been encountered in thy eXcava-
ton. The workmen werg making
about six feet day on eacbend. Like
the others there were fwo steam
pumps engaged at this Shaft, raising
the accumulated water and an air
pump driving air dowp to the level.
Besides this, large stetm engine was
employed in raising and lowering the
dump cars on the troy tramway. Al
together there are ped in the works
seven steam engine and nine steam
pumps besides an endless number OF
air pumps and othtr machinery.
And now, kind reader, if your pa.
thence is not alEady exhausted, ac-
company us in
A TRIP ON THB UNDERGROUND RAIL-
To the mysterious regions below and
YOU will at least enjoy spice of ad-
venture. We are perched in rather
uncertain position upon the bumper
at the reh end of the car and recline
ms low aspossible upon the tackle to
prevent any disagreeable collision of
head ana rafter. With the comforting
ran,ortthat % If the r0pe braa ks yOuill