The Savannah morning news., 1901-02-10

moved. 1t remained to arrange the coils
along his wire or cable in such a manner
that the right effects would be produced
by so adjusting each coil that the energy
sent through the circuit would be con-
served. 1t is in the adjustment of the
coils that the virtue of the invention con-
sists and the explanation is too techni-
cal for general comprehension. 1t is sur
fcient for the laymen 90 know that these
Pupin coils overcome the evil effects Of
electric resistance and make possible an
other great step in practical progress.
To illustrate the invention by Prof.
Pupin's present laboratory apparatus, $50
miles Of wire are supplied with $50 "chok-
ing coils one coil being inserted in every
mile of the circuit. IT was found that the
absorption of energy which generally
takes place along telegraph or telephone
circuit was greatly reduced. Accordingly
the same amount of energy sent out from
the transmtter would go much farther
with his apparatus. 1t was a problem of
equally distributing capacity, self-induc-
ton and resistance.
In It's outward appearance, Prof. Pupin's
laboratory presents a curious looking ap-
paratus over on each of five tables
stands a box about two feet square in
which is contained fifty miles Of wire rep
resenting If you will, fifty miles Of ocean
cable. From each box project connections
for 200 wires and these wires are attached
to fifty coils each coil being supplied with
four terminals. The coils themselves look
like small earthen jars open at both
ends; in reality they are merely made up
each of two coils Of wire of different sizes
carefully insulated from each other and
having the effect OF an ordinary induction
coil. Doubtless in the working out the
right relations between these two sets
of wires in the coil, Prof. Lupin encoun-
tered his greatest problem To get the
effect which should give the proper re-
sultant on his circuit was most import
ant, but once the relation was establish
ed, the principle could be applied CONNER
cialIy to any extent. 1t is In this part
of the apparatus entirely that the utility
of the invention consists. BY the use OF
these coils, properly adjusted and prop
erIy placed along the line of desired
communication, the system can be applied
TO any kind of electric communication.
with the circuit of $50 miles which Prof.
Pupin has arranged, he has found that
one coil every mile will bring the right
result. In the case of ocean cables this
proportion may not hold good, but Prof.
Pupin does not anticipate any difficulty
in adjusting his method TO the required
conditions. OF course, the use OF the APP
paratus will entail "a new system of con-
struction in telephone and telegraph
wires. our telephone wires OF the future
will have one Of Prof. Pupin's coils in
serted at certain intervals along the line
OF communication. For this reason rev.
olution in the presents ystem of cabling
cannot take place at once. new cable
must be laid. a Pupin cable II may be
called. which VIII dlffere from the Ordi-
nary cable by having perhaps thousands
of these little Induction coils attached to
II. With his $50 miles OF telephone or
telegraph circuit OF can be used for either
purpose) Prof Pupin has demonstrated to
the satisfaction OF experts that his sys-
tenn Is entirely practicable. The American
Telephone and Telegraph Company have
suficont faith IN the invention 10 make
a purchase Of It for half a million dollars
and 10 guarantee 10 tho inventor an an
nuity Of 1850. 1t Is their purpose 70 IN