one makers developed so essential a thing as a satisfactory wire.
Silver, which gave excellent results, was obviously too costly, and
copper, the other metal which had many desirable qualities, was too
soft. Thomas B. Doolittle solved this problem by inventing a hard-drawn
copper wire. A young man of twenty-two, John J. Carty, suggested a
simple device for exorcising the hundreds of "mysterious noises" that
had made the use of the telephone so agonizing. It was caused, Carty
pointed out, by the circumstance that the telephone, like the telegraph,
used a ground circuit for the return wire; the resultant scrapings and
moanings and howlings were merely the multitudinous voices of mother
earth herself. Mr. Carty began installing the metallic circuit in his
lines that is, he used wire, instead of the ground, to complete the
circuit. As a result of this improvement the telephone was immediately
cleared of these annoying interruptions. Mr. Carty, who is now Chief
Engineer of the American Telephone and Telegraph Company, and the man
who has superintended all its extensions in recent years, is one of
the three or four men who have done most to create the present system.
Another is Charles E. Scribner, who, by his invention of that intricate
device, the multiple switchboard, has converted the telephone exchange
into a smoothly working, orderly place. Scribner's multiple switchboard
dates from about 1890. It was Mr. Scribner also who replaced the
individual system of dry cells with one common battery located at the
central exchange, an improvement which saved the Company 4,000,000 dry
cells a year. Then Barrett discovered a method of twisting fifty pairs
of wires--since grown to 2400 pairs-into a cable, wrapping them in paper
and molding them in lead, and the wires were now taken from poles and
placed in conduits underground.

But perhaps the most romantic figure in telephone history, next to Bell,
is that of a humble Servian immigrant who came to this country as a boy
and obtained his first employment as a rubber in a Turkish bath. Michael
I. Pupin was graduated from Columbia, studied afterward in Germany, and
became absorbed in the new subject of electromechanics. In particular he
became interested in a telephone problem that had bothered the greatest
experts for years. One thing that had prevented the great extension of
the telephone, especially for long distance work, was the size of the
wire. Long distance lines up to 1900 dem