The Idaho Republican. [volume] (Blackfoot, Idaho) 1904-1932, 1922-12-07
CHAPTER Nv

In former chapter spoke OF the
difficulty of getting electricity de-
livered to q distant place by sending
It over wire, and I spoke Of its
resistance. If we get an electric
shock, it goes thru us so quickly it
does not seem that there could be
resistance but there is. A sled
drawn along on dry ground drags
hard. 1t is the resistance Of the
runners on the ground. Drag the
sled on wet ground and there is less
resistance, but If drawn acorss snow,
there is very little friction or re-
sistence.
In conducting electricity thru a
wire, the resistance increases as the
size of the wire decreases. A given
amount of curernt on wire makes
it warm; doubling the size Of the
wire cuts the resistance in half,
forcing the same amount of current
over a smaller wire would make 1t
hot with the greater resistance, and
would decompose the wire rapidly
would actually burn it out. There
fore, to transmit current over a
long distance, it is necessary that
there shall be a large enoubh cable
to carry it cool. Before they dis
covered the process called "step 1T
up" to high voltage to transmit 1t
long distances, and then "step 1t
down." to use 1t or distribute 1t in
small quantities, they had to use a
cable to carry given amount OF
lrs m 4 n n
larger and more expensive 1t was,
but as nearly as I can figure 1t out
from the encyclopedia 1t must have
taken about hundred and twenty
times as large cable as by the
method now in use. A power man
talking to me about it in the noise
of a power house said they can now
carry as much on an inch cable as
they could by the old method on a
see he was not very exact about it
either.
If we should place force pump
in our we'll, and pump the water out
thru half-inch pipe rod long to
a water trough, we could feel the
resistance of the water in the small
pipe very plainly. If we should in
crease the length of the pipe ten
rods long, we should have a hard
time to work the pump by hand and
get water thru except in dribble.
As we increased the length of the
pipe we should soon reach a stage
in resistance where it would split
the pipe if we tried to force the
quantity of water thru it. The re-
sistence of the water on the sides of
the pipe would be the reason for it.
If we kept taking of lengths of
pipe again, the pump would work
freer till we got back to the start
ing point. II one had meter in
serted in the pipe near the pump to
record the water pressure, he could
soon make scale to show just what
resistance there would be when de-
livering the water ten rods, twenty
rods and so on. Then If the pipes
broke off at some unknown point
out along the pipe line, he could re-
fer to his meter and tell just how
far out the break was.
In operating transmission cables
they have all such matters studied
out, and when lighting strikes a
pole in transmission line and
grounds the cable, the man in the
office can apply the test and tell just
about how far out on the line the
damage was tdone. If the line is
down between Blackfoot and Poca-
tello, they apply the test and know
whether to send out a crew from one
town or the other. On the line be-
tween Thousand Springs and Cald-
we'll, hangs cable lis miles long
without customer. It carries a
load Of 5000 horse power, and if it
were grounded they could apply the
test and call out a crew from the