anded wire about one-eighth
of an inch thick--as thick as a fairsized lead pencil; and, for this
reason, the New York-Chicago line, built in 1893, consumed 870,000
pounds of copper wire of this size. Naturally the enormous expense
stood in the way of any extended development. The same thickness also
interfered with cable extension. Only about a hundred wires could be
squeezed into one cable, against the eighteen hundred now compressed in
the same area. Because of these shortcomings, telephone progress, about
1900, was marking time, awaiting the arrival of a thin wire that would
do the work of a thick one. The importance of the problem is shown by
the fact that one-fourth of all the capital invested in the telephone
has been spent in copper. Professor Pupin, who had been a member of the
faculty of Columbia University since 1888, solved this problem in his
quiet laboratory and, by doing so, won the greatest prize in modern
telephone art. His researches resulted in the famous "Pupin coil" by the
expedient now known as "loading." When the scientists attempt to explain
this invention, they have to use all kinds of mathematical formulas and
curves and, in fact, they usually get to quarreling among themselves
over the points involved. What Professor Pupin has apparently done is
to free the wire from those miscellaneous disturbances known as
"induction." This Pupin invention involved another improvement
unsuspected by the inventor, which shows us the telephone in all its
mystery and beauty and even its sublimity. Soon after the Pupin coil
was introduced, it was discovered that, by crossing the wires of
two circuits at regular intervals, another unexplainable circuit was
induced. Because this third circuit travels apparently without wires,
in some manner which the scientists have not yet discovered, it is
appropriately known as the phantom circuit. The practical result is that
it is now possible to send three telephone messages and eight telegraph
messages over two pairs of wires--all at the same time. Professor
Pupin's invention has resulted in economies that amount to millions of
dollars, and has made possible long distance lines to practically every
part of the United States.

Thus many great inventive minds have produced the physical telephone.
We can point to several men--Bell, Blake, Carty, Scribner, Barrett,
Pupin--and say of each one, "Without his work the present telephone
system could not exist." But business genius, a