Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-02-18

still being in an experimental stage so far its
use in this country is concerned, although he
says that in his opinion there is
nothing experimental about it. line
is in operation Chicago and the
various features OF the system have been SO
carefully worked out and tested that it is now
he says, established commercial success
In speaking generally about his system Mr.
Wheeler describes il rs the trolley system with
the wires carried under ground instead of
wires strung on poles overhead. The trouble.
he says, with the use of electricity is that the
mechanical construction is defective. In this
road he claims that the construction is first
class, that it Is simple and can be managed
by those who are not trained in the use
of electrical devices. In view of the fact
that this road will be in the nature of a show
road and will be subject to the criticisms of
those who are afraid that the DAYS of the over
head trolley are numbered, special pains have
been taken to have the road run smoothly from
the first.
Any one who walks out U street while the
roadbed ia sill uncovered will be impressed
with the solid and substantial character of the
construction. The method of building an I'M
derground electric road is mnch the same as
that employed in building cable road. Be-
tween each track trenches are dug for the con-
duits. 1t is not necessary to go the same
depth in q cable road. The difference in
this particular is illustrated at the crossing
at l4th street, where the bottom of the conduit
along in its conduit. The electric conduit is
fourteen inches wide and twenty inches deep.
The rails are supported on cast-iron yokes
about four feet apart The sides of the
conduit are formed Of cast-iron plates which
extend up to the heavy slot rail. The yokes as
well ss the iron-lined conduit are imbedded in
concrete, while a layer of the same material is
over the entire area between the tracks, thus
forming foundation for the concrete pave
msnt. The appearance Of the roadbed when it
win be completed will be precisely the same as
that of the cable road. Instead, however, of
having cable in the conduit there will be two
copper wires The merit of this system lies in
the insulation Of the wires and the metallic
circuit.
THE INsULAToRs.
On each side of the slot iron rods are fastened
through holes in the yokes. Between these
rods are held blocks Of composition, which are
composed in the main of mica. These are the
insulators, and they are designed to prevent
any Of the precious fluid from escaping Brass
clamps are attached to the BLOCKS which clasp
the wires in the grooves, which are on each dde.
The under side Of the wires thus left with
an unobstructed surface, along which the
wheels Of the trolley move freely. In
order to provide for the movement
caused by the swaying Of the car when in mo-
ton the wheels which connect the trolley with
the conducting wires are attached by joint
which has three movements-one like that OF
the wrist, another like that of the lower
fall arm movement The conductors are 30
firmly Get in place that they can support the
weight Of man without sagging. In addition
| to being . substantiAl part OF the work the ex-
pansion and contraction Of the wire by the
effects Of heat and cold b also guarded against