The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1901-06-16
PROGRESS
IN PRST TWO DECADES
Revolution Has Been Wrought in Al
most Every Industry-The
End Not Yet Reached.

fetal lights, followed as a natural result
Of the generation of electricity by the
dynamo, and each light absorbs nearly
one horse power. There are more than
10000 street arc lamps burning tonight in
greater New York, and forty-two tons
of coal every hour are consumed. One
horse power can furnish current enough
to keep about twelve inoandescent cleo
trio lamps lighted, and in Greater New
York there are now in use over 1000, geo
Of these lamps. The total power requir-
ed for the electric lighting of this great
city is certainly not less than 100000 horse
power, or more than the combined equip
ments of all the ships of the United
States navy.
THE TROLLEY CAR.
Let Us turn for moment to that other
common application of eleetricity-the
trolley car-where the power to move
ponderous mass Of several tons is CON
veyed along a slender wire A trolley
road consists of three elements-the
power plant, where electric currents are
generated; the overhead and underground
conducting systems, by which the cur
rents are led to the cars and the cars,
on which is the motive power apparatus
which converts the electrical energy back
into mocha effort, electricity being
only the intermediary between the en-
CINE at the power plant and the car. At
the power house of a modern system are
large and powerful steam engines turn
ing dynamos These machines are simply
electricity pumps which are constantly
filing a reservoir-the overhead and I'M
foreground wires of the trolley system
and keeping it full to a certain pressure
If there are no cars running, and the
reservoir network of overhead wires is
properly electricity-tight- Is, if there
are no leaks-there will be no demand
for power from the station and no cur
rent will flow. lie engines and dynamos
will turn idly.
When the motorman turns the handle
of his controller, he simply opens q valve
so to speak and the electric current
flows from the overhead conductors down
the trolley, through the controller into
the motor which begins to turn; thence
to the wheels and track and back by
the rails to the power house None Of
it Is lost, none of it is wasted, and las
much returns to the power plant as went
out, but it's pressure falls in going
through the motor, and it gives up its
energy in moving the car. In precisely
the same measure that the cars require
power Is current withdrawn from the
overhead reservoir, slender out potent
and just so much must the engines and
dyndmos at lie generating station work
to keep UP tine pressure.
NIAGARAs GREAT POWER PLANT.
An immense station at Niagara Falls,
taking its power from the fall of water
there, supplies the city Of Buffalo, TWEEN
ty-six miles away, with every particle of
electric current required in that city for
lighting and local power purposes. All
the lighting for the Pan-American ex-
position is also supplied by Niagara
Fals-5,000 horse power This Is only a
typical station. Other vast water powers
are being utilized in the same way.
Wherever it is possible to use this long
distance electric power, snnokestacbs are
disappearing and in their places are
transformed stations to which electric
current is brought at high voltages and
transformed down and distributed. En-
gines, boilers, ashes, smoke and dirt are
all disappearing, and a clearly attired
and heen-eyed electrician stands at the
switchboard controlling every detail and
noting at a single glance at mis- instru-
ments of measurement the requirements
of his customers. He has superseded at
his station the engineer the fireman, the
coal man and the ash man.
The storage battery, the electric heater,
the electric furnace, electrO-metallurgy
the X-ray, are other fields of electricity
The A-ray has proved a powerful inStru-
menC IN the n2ndS OF the surgeon, and
been Of inestimable value to suffering hu-
mainly. This strange form of lig t.
which shines clearly through the flesh
and penetrates through a wooden board
as a sunbeam does glass, reveals by the
shadows it casts the bones or foreign
objects in the body. This now almost
trite fact is one of the most astonish ng
that electrical science has yet given the
world. 1 asked a scientific friend to ex-
plain in everyday parlance the opera
tion of the So-called Roentgen or X-ray.
He told me that: 1.-The X-ray is a rapid
transverse undulation set up by the I'M
pact of gaseous molecular ions driven by
a cathode stream. which is produced by
the action of a high electro-motive force
upon matter in a condition of extreme
gaseous tenuity." I hope this makes it
very cleari
TELEPHONING ACROSS THE OCEAN.
An interesting modern application Of
electricity is wireless telegraphy. 1t has
been operated over a distance of 200 miles,
and if it becomes selective. that Is, so
one set of electric waves will not be af-
fected by another set, It Is destined to
have an unlimited use. Another modern
development, the invention of Prof. Pu-
pin, of Columbia college, has made ocean
telephony probable. 1t consists of the
insertion of a number Of coils in the ca
BILE which set The interfering elements to