Evening star., 1897-01-16

PraCtNdi working or the electric current
when making rs dynamo and his expert
ence with his motor added a good deal
to his stock of knowledge in that direc-
tion- The most important of his discoy-
cries was tha. electricity is really a form
OF force and not an independent force of
ITSELF Indeed, as now commercially de-
velcped and used. the mystic current is
much like the belt that carries the power
from the fly wheel of a steam engine 10 a
piece of machinery. or like a stream Of
water set to flowing through a channel
that retrrrs upon itself, the power depend
Ing altogether upon the swiftness of flow
ana the volume of current. Elec trcity Is
an exceedingly useful agent and its use
py man has fastened the progress of the
"9rid enormously, as has also the use of
steam But electricity has been profitably
develored. thus far, only by the applica-
ton of some outside force like steam. a
waterfall. or a windmill to a dynamo or
electrical machine.
IL is common enough for men to speak of
eiectrlcity IS II 1t were produced by a dy-
namo but John learned from his friend
that electricity is not produced 1t is
everywhere and always present; asleep.
so 10 speak. in every one of natures sub
stances What the dynamo does is 70
awaken 1t and set it TO circulating, as
wheel made Ike steamer paddle wheel
would start the water in a circular trough
10 rUEnirg. Like the water in such a
trough, the electric current, once started
always flows back to its source going from
the dyEdmo through one wire of the cir
cult and returning through the other. Now.
IN the Cese Of the circular stream of wa
ter, II second wheel were placed in the
trough 1t would necessarily be turned by
the flowing water whenever the first one
was in notion The dynamo then is like
the hrst- or paddle wheel, in the circular
trough. while the motor is like the second
or water wheel As much power can be
hl
revolve the first, lees the waste by friction
and the power gi"en off by an electric
motor bears the same rela ation to that ex-
penCed on the dynamo
After John had mastered this he learned
that there are other ways of developing
the electric current than by the applica-
Con or power to dynamo. One of them
Is by decomposing certain metals by means
OF ACIDS 1t Is too expensive for the profit
able development of any but the Iightest
currents. such are used to ring bells
operate telegraphs and telephones and the
IKE, Dut When John found what 1t really
amounted to he thought 1t the most won
oerful thing he had ever heard of. All
metals and other forms of organized mat
Ter. John learned have reached their pres
eht condition through the workings of i'm
mense natural forces. But no force Is lost
at any time. and natures forces expended
IN producing mineral. or a tree. for in
stance. are stored in the mineral or tree
and so remain until the elements are do
composed. 1t Is from the accommodation nj
elements thus stored that we get most OF
the power we use for our machinery. for
.he running or our trains and the nayiga-
tion OF our steamships
When we decompose zinc and copner In
an electrical battery we release the forces
stored by nature in these metals and
chanse II into that form of force which we
call electricity. When we burn a I,Imn NJ
coal or piece of wood under a steam
DolIer We release the power stored IN in
the coal or the wood and change 1t into the
!orrn OF force we call heat. Heat changes
the water into steam. and we use IL I'm the
steam engine and by properly applyine its
power 10 a dynamo get an electric current
: His current we use exactly as belts or
engine from the place where II Is produced
70 the place where we wish to use il Souo-
time, II is believed by Mr. Edison Mr.
Tesla and all the other ingenious men who
are studying electricity. We shall be able
10 make the current directly from the burn
Ing or decomposition OF coal, and then we
ran get rid of the steam engine but until
th-h We shall have to consider the electric
current hothlnS more or less than an agent
Its work. Wv
Helped to Make the Motor
All this. and good deal more which
there Is not room here to explain. John
learned from his friend, the electrician
VINO helped In making the motor, as he had
before helped In making the dynamo. and
directed the boy in getting materials to-
gether. These materials were;
Two pounds of No Is cotton-covered COP
Ter wire. f
TWO plates of iron. six inches square and
cne-quarter inch thick
"A Strip or sheet copper. three inches
long ty two inches wide
A cylindrical piece of iron, four inches
long by two inches in diameter, with a
hoIe through the center and two deep
grooves running from end TO end
An IRON rod, six and one-half inches Ion q
ehu ohe-quarter OF an inch in diameter
A ie" pieces OF wood. a strip Of tin and
Some screws.
Inese materials having been gathered to-
sether, the armature, consisting of core.
smart and sorne small parts. first received
al,ehtlon- For the core the large grooved
cylindrical piece of iron was used: for the
smart the iron rod. which fitted snugly
INTO the hoie through the core. and being
passed completely through was allowed to
project an inch at one end and an inch and
haif at the other. The core and shaft
are shown at figure 1. Next a thickness OF
paper was fitted into the grooves, SO as to
form complete insulation, and then the