rt it was Carty's task to direct the work of this staff and
to see that all moved smoothly and in the right direction. Just as
the telephone was more complex than the telegraph, and the wireless
telegraph than the telephone, so the apparatus used in wireless
telephony is even more complex and technical. Working with the
intricate mechanisms and delicate apparatus, one part after another
was improved and adapted to the task at hand.

To the devices of Carty and his associates was added the extremely
delicate detector that was needed. This was the invention of Dr.
Lee de Forest, an American inventor and a graduate of the Sheffield
Technical School of Yale University. De Forest's contribution was
a lamp instrument, a three-step audion amplifier. This is to the
wireless telephone what the coherer is to the wireless telegraph. It
is so delicate that the faintest currents coming through the ether
will stimulate it and serve to set in motion local sources of
electrical energy so that the waves received are magnified to a point
where they will produce sound.

By the spring of 1915, but a few months after the transcontinental
telephone line had been put in operation, Carty had his wireless
telephone apparatus ready for extended tests. A small experimental
tower was set up at Montauk Point, Long Island, and another was
borrowed at Wilmington, Delaware. The tests were successful, and the
experimenters found that they could talk freely with each other. Soon
they talked over a thousand miles, from the tower at Montauk Point
to another at St. Simon's Island, Georgia. This in itself was a great
achievement, but the world was not told of it. "Do it first and then
talk about it" is the maxim with Theodore Vail and his telephone men.
This was but a beginning, and Carty had far more wonderful things in
mind.

It was on the 29th of September, 1915, that Carty conducted the
demonstrations which thrilled the world and showed that wireless
telephony was an accomplished fact. Sitting in his office in New York,
President Theodore Vail spoke into his desk telephone of the familiar
type. The wires carried his words to the towers of the Navy wireless
station at Arlington, Virginia, where they were delivered to the
sending apparatus of the wireless telephone. Leaping into space, they
traveled in every direction through the ether. The antenna of the
wireless station at Mare Island, California, caught part of the waves
and they were amplified so