The Hawaiian gazette., 1896-10-06

tie calculation. 1t is generally located
as follows: 1t is known that the re-
sistance which the wire offers to the
current averages a specified quantity
to the mile. When break or fault
occurs the resistance of a cable is
measured in the cable station. This
can be readily done, because the cir
cult will generally complete itself
through the earth. When the resist
ance has been measured, it is easy to
find out where the break is by dividing
the whole amount by the average re-
sistance per mile. 1t may then be
found that the break is two, three, four
or five hundred miles off shore, as the
case may happen to be. A cable-re-
pairing steamer, with a full corps of
electricians on board, Immediately
starts for the spot where the break is
supposed to be. This is an easy mat
ter, for when cables are laid the lati-
tude and longitude of the cable-laying
ship is taken as each mile of the cable
is paid out. If the break, as dete-min-
ed by the resistance, is, say, 500 miles
off shore the captain of the repair boat
directs his vessel to the particular
junction of latitude and longitude
which was encouI tered when the 500
mile mark of the cable was first laid
Having arrived at what he conceives
to be the proper vicinity, he steers his
vessel into course at right angles to
the course held by the cable. He then
throws an iron overheard and pro-
ceeds to grapple for the cable.
DIFFERENCE IN THE PULL.
He knows when he has caught the
cable by~the difference in the pull
from the pull which is felt when a rock
is truck. A rock when caught by the
cable will finally let go with a jerk
but the cable when caught will exert
a long, steady and obstinate pull as it
is hauled to the surface. There is also
a patent graphing iron which cuts
through the cable covering and electri-
cally rings a bell. Having picked up
the cable, the chief electrician on board
the boat cuts through the covering, if
IL has not already been cut through by
the graphing iron, and, attaching a
transmitter to the core, sends a signal
through the cable. If he gets an an
swer from this end of the line he knows
of course that the break must be
beyond him, or vice versa, if the an
swer comes from the European end
AS he now knows in which direction
from the vessel the break must be, he
proceeds to measure the resistance of
the broken" end, in order to see ex-
actly what its distance is from the
vessel
If it is not far, say, four or five miles,
the captain of the vessel proceeds to
underrun the cable until the delinquent
spot is reached, when it is an easy mat
ter to repair the break or to put in a
new section of cable If the break is
found to be number of miles away.
the part which has been picked up is
attached to buoy, and the vessel
steams away to what further observa-
ton has determined to be the required
spot. The cable is picked up again
and signal is sent through.
If the answer is from Europe instead
of from this end of the line. it follows
that the break must be somewhere be-
tween the parts of the cable which have
been picked up. The precise spot can
then be easily determined and repairs
can be made. Sometimes the work is
very expeditions, but in stormy sea-
sons of the year it has often been
month before the break has been found.
1t has also happened that in graphing
for cable the repair boat has picked
up by mistake the cable of another
company. This has happened three or
four times. but the courtesy of the
cable companies to each other has al
ways excused it.