ty once said that
on account of his distinguished scientific attainments and wonderful
telephonic inventions, Professor Pupin would rank in history alongside
of Bell himself.

We have seen how Alexander Graham Bell, standing in the little room in
Boston, spoke through the crude telephone he had constructed the first
words ever carried over a wire, and how these words were heard and
understood by his associate, Thomas Watson. This was in 1876, and it
was in January of 1915--less than forty years later--that these
two men talked across the continent. The transcontinental line was
complete. Bell in the offices of the company in New York talked freely
with Watson in San Francisco, and all in the most conversational
tone, without a trace of the difficulty that had attended their first
conversation over the short line. Thus, within the span of a single
life the telephone had been developed from a crude instrument which
transmitted speech with difficulty over a wire a hundred feet long,
until one could be heard perfectly, though over three thousand miles
of wire intervened.

The spoken word travels across the continent almost instantaneously,
far faster than the speed of sound. If it were possible for one to be
heard in San Francisco as he shouted from New York through the air,
four hours would be required before the sound would arrive. Thus the
telephone has been brought to a point of perfection where it carries
sound by electricity and reproduces it again far more rapidly and
efficiently than sound can be transmitted through its natural medium.

XX

TELEPHONING THROUGH SPACE

The Search for the Wireless Telephone--Early Successes--Carty and
His Assistants Seek the Wireless Telephone--The Task Before Them--De
Forest's Amplifier--Experimental Success Achieved--The
Test--Honolulu and Paris Hear Arlington--The Future.

No sooner had Marconi placed the wireless telegraph at the service of
the world than men of science of all nations began the search for
the wireless telephone. But the vibrations necessary to reproduce the
sound of the human voice are so infinitely more complex than those
which will suffice to carry signals representing the dots and
dashes of the telegraph code that the problem long defied solution.
Scientists attacked the problem with vigor, and various means of
wireless telephony were developed, without any being produced which
were effective over sufficient ranges to make them re