Gold Hill daily news. [volume] (Gold Hill, N.T. [Nev.]) 1863-1882, 1873-10-13

Very few people, even professional
men, are aware Of the immense diff
culties to be overcome In regard to
projecting the line from the surface
down to the bottom of the shaft, from
whence they have to be continued both
east and west in order to make an ac-
curate connection of the several drifts
on the line of the tunnel. The header.
ir will be remembered, was started
from the mouth of the tunnel, in the
town of Sutro, and Is being pushed
rapidly ahead in the direction Of Mt.
Davidson. The drift is being Il In n
perfectly straight line, rising westerly
with a grade of two inches to every
100 feet.
Shaft No. l is located 81 feet 0 inches
of the center line in u northerly direc-
ton, and Is distant from the mouth
of the tunnel 1855 feet. In order
to start a driit from the bottom
of shaft No. l, to meet the header
coming from the town Of Sutro, 1t was
found necessary to first run back q
feet 0 inches in u southerly direction
from the bottom Of the shaft, until the
center lire of the tunnel was reached,
thence to turn a right angle eastward
", aud run in this course until the
header is met. In order to effect an
exact connection between header and
shaft extreme accuracy was necessary
in surveying these lines. A serious
embarrassment to correct surveying
originated from the placing ola boiler
on the surface just ut the point where
the line OF the tunnel crosses the offset
line of the shaft. 10 as to prevent plac-
ing the instrument over this very I'M
portant point. 1t therefore became
necessary to lay Off the rectan-
gular offset lines In front OF
the boiler past the shaft, thence
to measure with Offsets so rs to get
n parallel line over the top Of the
shaft. aud from this parallel line to
plumb down to the bottom OF the
Shaft, 523 feet S inches in depth. thence
take this line at the bottom and pro-
long it southerly 81 feet and 0 inches
to the centre line Of the tunnel, and
from this point turn a right angle and
start the east and west drifts. From
| the above mentioned statement it will
be c that the difficulties encounter
ed in making the survey were much
greater than those connected with the
Hoosac Tunnel, the shaft Of the latter
being exactly on a line Of the tunnel
itself. The longest diameter Of the
| Hoosac shalt Is % feet and Is placed In
the line of the tunnel so that this line
could be projected directly in the line
| Of the tunnel aud then be prolonged
both ways. The longest base line that
could be projected down the Sutro
Tunnel shalt was six feet eight
inches in length, provided that
one plumb bob is hung down
the pump shaft, while the other Is
hanging down in the hoist shaft. but
the pump shaft Is almost entirely
filled with steam pipe, exhaust pipe,
pump column and its braces, n a
ladder way. Plumbing down the shaft
was not considered reliable, rs the wire
might touch at some point or another ;
the shaft also being so hot from the
exhaust steam as to prevent an inspec-
ton Of the plumb.bob, therefore. the
hoist shaft giving a base line Of three
feet. one inch In length, had to be de-
pended upon tor projecting the line OF
the tunnel down In the bottom OF the
shaft. The slightest variation made,
even on the surface in this short base
line, would result d~lsastrously In
throwing the east drift a long way oil
the true line.
Approaching the difficulties preVi.
ously enumerated, .tle Sutro Tunnel
Company cast about for civil en-
gincer equal to the emergency, and
eventually were fortunate enough to
enlist In the enterprise MIR. ii. Sehuss-
Ter, Chief Engineer Of the Spring val.
lev Water Company, and still later OIL
the Virginia and Gold Hill water
| Company. Mr.. Schussler entered upon
his work with his usual energy and ar
dor. Under his careful and accurate
surveying the drifts have been run
straight as an arrow. lie has been
ably assisted by Ross +. Browne. a
Young engineer of marked ability. The
driving OF the tunnel is being prose-
cuted With the greatest vigor. Our re
porter rode into the tunnel nearly q
mile OIL a back-action car, an ill-na'
tured mule being the propellinS pow
err. The two headers 1t present arc
only lO2 feet apart, aud the blasting
and drill hammering can be distinctly
heard in the respective faces.