The daily Gate City. [volume] (Keokuk, Iowa) 1855-1916, 1911-08-31

completed and power ready for trans
mission to those cities where con-
tracts have or will be made, Besides
supplying the local consumption,
other cities will apply for the current,
ST. Louis being the most extreme
point where the current will be car
ried.
1t is easy enough to understand
just how falling water will turn a
water wheel and how this wheel can
be made to whirl an electric dynamo,
or generator, but how this power is
carried away to the city remains a
blank and puzzhng mystery to most o..
US unskilled in interpreting electrical
lore.
There are two ways In which this
electrical horse power can be carried
over the hills to the cities. In the first
place 1t could literally be packed over
the road in basket just like SO many
eggs; and next it can be sent along a
certain metallic path with ease, econ
omy and certainty To carry this
enormous amount of energy hundred
miles In a basket would necessitate
its being used to charge large storage
batteries and these batteries could
be carried by horse power or the rail
roads to the cities where they were
to be used. When the batteries were
discharged they would have to be re-
turned for recharging. All this
would be expensive, not to mention
that it would be unhandy and far from
being in accordance with business
methods of this day and age.
The electrical engineers quickly
found a way to transmit this Juice"
to paying market. This was no small
task, remember, because with the
first dynamos used 1t was quite i'm
possible to transmit electrical energy
to any considerable distance. Three
things made long distance transmits
sion of electricity possible alternat-
ing current, the development of the
former. The principle involved in
sending electricity over great dis
tances is to use very high voltage
or pressure with a CORRESPONDENCE
small current The power transmitted
over wire Is represented by the
product of volts times amperes, or
pressure times volume To transmit
! a lot of power over a wire, therefore,
if you use very high voltage you
can get along with comparatively few
amperes. AS the size Of the wire is
proportional to the number Of amperes
carried, you can get along with
small wire by using high tension
voltage and low amperage. 1t is just
the same as though you were to I'M
dertake to pump a given amount of
water through pipe. If you were to
use a pressure of ten pounds per
square inch, you would need to have
a large pipe to get the water through
very fast On the other hand If you
were to use 100 pounds pressure per
square inch, you could get the same
amount of water through very much
smaller pipe, thereby saving money
on the pipe.
4 Before alternating current came In
to use, it was impossible to obtain
current at high voltage except by
building special and very costly
dynamo, and even then they could
only get a few thousand volts. To
attempt to transmit many miles with
only, say, five OR six thousand volts
available pressure meant that to set
much power over a line a very great
current in amperes would need to re
sent over it-remember power equals
volts times amperes. AS conse-
quence the copper wires would have
been so large and costly as to be out
of the question. They would have
been massive bars of copper.
Then along came alternating cur.
rent, and with it the transformer, a
comparatively inexpensive device
which will take the current from an
alternating dynamo and step up the
voltage almost to any point desired
Suddenly, then engineers had equip
ment available for producing current
at high votages, first 10000 to $4,000
and lately even at $4,000 volts. hen
long distance transmission became
possible, for with the high voltages ii
was possible to use wires email
enough so that to transmit curren,
over a distance of several hundred
miles, would leave a margin of profit
in the difference between miles
the interest on the money in
vested in copper to the receipts from
the sale of power.
The development of long distance
transmission from fifteen or twenty
miles, at first to over 800 miles, has
been largely matter Of developing
insulators which would prevent the
current from ieaking out of or slop
: ping over from the line. Lately. they
have produced insulators which will
carry $4,000 volt wires safely. Wher
100000 volt insulators are made. wires
will be reduced in size and the line:
may then increase in radius another
hundred miles.
Without a food of artificial ligh
moving pictures would be impossible
The essential features of a motor