St. Paul daily globe. [volume] (Saint Paul, Minn.) 1884-1896, 1889-04-28

etreet crossed by it and the other is on
the opposite side. These are round eX-
cavationS some four feet in diameter
lined with the asphalt concrete of which
the conduitS are made and opening on
the street through round hole large
enough to let man through. When in
the ordinary condition these holes are
covered with heavy iron curb provided
with double lid. The lower lid is held
down by gun metal cross bar and
screw, and fastened on top of tubular
India rubber gasket, which is in a
groove of the lid. When this is put on
and the fastenings are covered the.whole
is Theoretically sealed, perfectly air
tight. The second lid is loose and is
Hush with the pavement.
You have seen how two conduits,
made of asphalt, have been laid along
those trenches, one on each side of it,
making them two feet apart. You know
what the cOnduitS are? They are the
rectangular, black pipes, the joints of
which are about four feet long: they
were lying in piles all along the street
all the week. These, when laid, were
fastened together by means of steel fer
rules, with paper covers, and the black
asphalt poured while hot over the joint,
making it almost perfect. In each of
1wenty-four holes, or properly speaking,
ducts through which the wires are to
run. The number of ducts to the con-
duit In the Minneapolis subways are
six, nine and twelve"
GLOW many wires will that number
OF duets accommodates"
'Well, now, let me explain that. AS
j told you, there are two conduits. one
son either side of the trench. One is for
the light current wires, that is for tele-
graph and telephone wires, and the
other is for electric light, power and
heat, or the heavy current wires. These
are separated in this way so that the
heavy current shall not have an effect
on the light currents, and as this asphalt
Is a perfect nOn-cOnductOr, the wires
are as perfectly insulated as if they
were glass, and the effect is gained
Now, to answer your question. Of the
light current wires the tWelve-duct con-
duits are capable of containing 1850
wires. l am asked sometimes how long
1t will be before the pavement must be
torn up again and more room made for
wires, and will show you that it will
be an indefinitely long time by telling
you that now on Nicollet there are $50
light current wires and we have accom-
modatiOnS in our cOnduitS for the 1900.
These cOnduitS are laid on solid plank
foundations and are imperishable, so in
your time there is no need of ever tear
Ing up the street again unless tile city
has a miraculous growth"
"And now to come to the question
that bothers everyone, how to get the
wires In. One man said to me: 4 sup
pose when you get ready to put your
wires in all this work must be torn up
and string 'em through hut?' And I
have answered hundreds of Just as alb
surd queries. The process IS simple
one. The workmen have large num-
Der of hollow iron rods about three feet
long, that are supplied with male and
female screws at the ends, like jointed
fishing rods. One of these is started
into duct in which the cable is to be
placed. A second rod is screwed to it
and pushed in and a third screwed to
1t, and so on till the first one appears at
The man-hole block above.
"a small line is fastened to the last
rod, and man at the next man-hole
pulls it through. unscrewing the rods,
bne by one, until the line reaches him.