The morning news. [volume] (Savannah, Ga.) 1887-1900, 1895-01-13
MAKING A DYNAMO.
It Is Simple Machine, Notwithstand-
ing It Does Wonderful Things.

rum luc OuiCdBO RECORD.
For four months the high school schol-
airs had been exploring the fascinating
fields Of natural philosophy. For sixteen
school weeks they had talked of light,
heat, gravitation, acoustics, molecular at
traction, magnetism and electricity. and
the professor had made many expert
ments and demonstrations with his polish
ed apparatus. Stin the high school boy
was in the dark.
He was specially interested in cleo
tricity, and had made a simple galvanic
battery out of butter jar strips of zinc
and copper and sulphurc acid He never
passed the power house of the electric
street car line without looking through
the windows at the busy dynamos and in
dustrious engines. The young electrician
in charge of the plant noticed him anu
one Saturday afternoon invited him in.
He was somewhat surprised when the
high school boy after a critical inspection
of one Of the humming electrical gener-
ators abruptly asked: What makes the
electricity"
Those dynamos," replied the electri-
clan. The armature revolving in the
magnetic field catches the electricity and
sends it out to work through those wires
which go outside to the trolley and cleo
trio light wires"
yes, know that. Our professor has
told us that But still l don't know what
electricity is and how that machine makes
it,"
The electrician led the high school boy
away from the dynamos to a little room
fitted up as a repair shop. Taking I'D a
horseshoe steel magnet he said: You
know what this Is. 1t is a steel or per
manent magnet. 1t VIII pick up nails,
needles, tacks or any light thing made of
iron or steel. 1t attracts these things
to it and they stick to the ends or roles
of the magnet. Here are a lot Of iron fl
ings. When L lay the magnet on This
sheet of paper and sprinkle the iron FL
tngs around it you see how the little bits
of iron cling to the poles. They cluster
thickly around the poles and to each
other, so that each pole looks as though
1t had bushy hair. Now, as long as those
iron Filings are attracted to the magnet
they are in the magnetic field. If |
move them so far from the poles that
they are not influenced by the magnet
they are outside of the magnetic field
Around every steel magnet is a certain
space called the tmagneS.c fasl. The
magnetic field has in it springlng from
the magnet what we call lines of force
These come out from the magnet in all
directions, but the farther they set from
the poles the weaker they grow.
'LonS before the dynamo-electric ma
chine was thought OF it was found that
if the needle of a compass-which is
nothing but a straight or bar steel mae
net-Was brought very near a
wire through which an cleo
trio current was passing, the
needle whirled around on its pivot until
it stood at right angles to the wire. and
of course at right angles to the direction
of the electric current. AT that time the
electric current was obtained generally
by means of galvanic batteries. A few
years after the discovery was made thar
compass needle was moved when
brought within the magnetic field of a
conductor, as we call the wire which car
ries an electrical current, il was found
that if a soft iron rod was wound with
wire, and an electrical current from a
galvanic battery was sent through the
wire, the iron rod became a powerful
magnet, but that it lost its magnetic
power the instant the current was cut
off. This was the first electro-maenet
and electromagnetic are important parts
of the dynamo which generates our cur
rent.
Just before the first electro-magnet
was made, and that was nearly seventy
years ago, it was found that if a wire was
passed through the lines of force in a
magnet field an electric current was pro-
duced. 1t was not known why the cur
rent was produced, simply because the
wire was moved around close to the steel
magnet. and it is not known to-day, for
to this hour no one knows Just what that
mysterious energy we call electricity is.
As long as the wire is moved within the
magnetic field electricity is produced but
the wire must move. There must be a
change within the lines of force. If the
wire is held still and the magnet is moved
a current of electricity is set up in the
wire just the same, for in moving the