The record-union., 1895-06-22
new ELECTRIC STREET CAR MOTOR,
Or, Rather, the Present System is
Reversed.
A San Francisosn's Idea for an Under
ground Wire, Instead OF the
Overhead Plan.

For long time mechanical and cleo
trical experts have been endeayoring to
solve the problem of a cheap yet perfect
underground electric system, says the
San Francisco Call. There are any num-
Der of high-priced inventions, but it is
Just this one thing of cost that prevents
their coming into general use. New
York is to-day putting into operation a
system in which the overhead wire is
done away with, but the cost is immense,
hence it is not likely to come into gen.
eral use.
The problem OF oheapness as well az
perfect service seems TO have been solved
by c. NJ. Bridges. San Franciscan. who
has his idea, in the shape Of well-built
miniature road and cars, now on exhibi-
ton in the History building. The model
consists OF sixtY-foot track of circular
shape. with up and down grades, switches
and sharp curves. Over this speeds a
miniature car, the open-work of the
track showing the manner in which the
car receives the motive power.
Underneath the car is a long flexible
metal bar, which is held in position by a
front, rear and center support. In the
conduit at intervals the length of the ear,
or, correctly speaking, the metal bar, are
placed small rollers through which the
necessary current is supplied. This cur
rent comes from wires laid between the
tracks in terra Gotta or iron pipes con-
necied with each roller by q small wire.
These rollers are topheavy, so to speak,
and until lifted up by the iron rod under
meath the car act as a cutoff for the deadly
current Starting at q given point the
natal rod lifts OF tn9SH little roll
lers, the motorman turns on the current
and the car speeds to the next, just reach
ing II as the starting point roller, released
by the car, drops back to its place. By
this ingenious yet simple device con-
tinuous current is kept up, yet it is never
open except NJ the point where the car
rests.
"We can place our system on every
cable road in San Francisco and not inter-
fere with traffic one moment" said Mr..
Bridges, the inventor. yesterday.
''SnOuld any of the contact rollers get
out of order another can be put in with
out the slightest delay to traffic. 1t is
easy TO keep in order because none of the
parts are concealed in the conduit. At
intervals Of every 200 or 800 feet the con-
duit will have a catch basin, and as each
is provided with a sweeper or scraper
any debris falling into the conduit would
be carried to the basin, thus making 1t an
easy matter to keep clean. The construc-
ton OF a road of this kind would be about
the same as a cable, but the wiring and
other material can be placed underneath
much cheaper than the trolley.
Another thing In favor of my system
is, that should the conduit become filled
with water, il would not interfere with
running the road in the least"
Nearly every railroad man and cleo
trician in San Francisco has thoroughly
examined the system invented by Mr..
Bridges. and they all unite in saying that
il is perfect.
There is some talk of the Market-street
people taking hold Of Mr.. Bridges patent
Or at least giving it trial on one OF
their roads.
A very ingenious device in connection
with the new aystem is the manner in
which the steep-hiIl difficulty Is over
come AS the car approaches the foot OF
a grade the current is shut off, when an
endless chain, working automatically
grasps g projecting rod, pulls the car up
the incline, and by similar automatic
arrangement releases it when the top is
reached,