October 1970 Popular Electronics
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
Just as you will never get everyone to agree
on who was the first person to successfully fly a powered aircraft (Wright, Whitehead, Curtiss, etc.),
there will never be a consensus on who invented the radio. Most people would probably say it was Marconi,
but this author makes a case for none other than Thomas Edison. Before you dismiss the opinion, read
A Question of Semantics
Who Did Invent Radio?
By Fred Shunaman
In all probability
there will never be total agreement on the question of who actually discovered radio. In fact, the word
"radio" itself does not stand up to a strict historical interpretation. Does the "first radio" mean
the first two-way wireless communication? Or a one-way wireless transmission? Or would a minor laboratory
demonstration and a patent establish the precedency of the discoverer/inventor?
In one way or another, Marconi, Popov, Loomis, Butterfield, Lodge, Hertz and Tesla all qualify as
discoverers of radio. However, history now shows that none of these men has the supporting evidence
of discovery that belongs to Thomas Alva Edison-to whom the honor may rightfully belong.
language difficulty may have cost Edison the credit for first discovering and using radio as a means
of communication. He announced the discovery of "etheric force" when Marconi was only a year old and
while Tesla was still attending school. And, in 1885, two years before Hertz announced the discovery
of electromagnetic waves, Edison applied for a patent on a complete wireless system. Submitted with
his application were patent drawings of radio towers and antennas on the masts of ships.
It All Began. During the evening of November 22, 1875, Edison was studying the action of a magnetic
vibrator. He noticed a tiny spark between the armature and core of the vibrator as the armature approached
the core. Suspecting faulty insulation, he checked the coil but found everything in order.
However, Edison reported that; "If we touched any part of the vibrator we got the spark," and that
"the larger the body of iron touched to the vibrator, the larger the spark." If a wire was connected
between the vibrator and a gas jet on the wall, a spark could be drawn from the gas pipes anywhere in
Above is one of the drawings from Edison's Patent No. 465,971, Dec. 29, 1891, describing
a "Means for Transmitting Signals Electrically." Particularly interested in transmitting across bodies
of water, he showed high towers and ships carrying "condensing surfaces" (which we would call antennas).
At the right is an enlargement of the insert, in which Edison described how signal was generated and
transmitted to antenna.
Then Edison performed the experiment that Hertz was to do 17 years later; he found that "if you turn
the wire round on itself and let the point of the wire touch any part of itself, you get a spark ....
This is simply wonderful and a good proof that the cause of the spark is not now known force."
Next, Edison constructed a demonstration apparatus and revealed his new etheric force" to the Polyclinic
Club of the American Institute. Many of the members seemed upset by the name he had chosen for the new
effect. But Edison was undaunted, and he predicted (in the January 1876 issue of the Operator, a telegrapher's
magazine) that the new force might become the telegraphic medium of the future. He is quoted as having
stated: "The cumbersome appliances of transmitting ordinary electricity, such as telegraph poles, insulating
knobs, cable sheathings, and so on, may be left out of the problem of quick and easy telegraphic transmission,
and a great saving of time and labor accomplished."
Edison's "black box" 1881 demonstration had graphite points which could be connected
to an external circuit. The extension eye-shade permitted viewer to see, jumping between the contacts,
sparks unlike any known to an electrical phenomenon at that period.
The Scientific American of December 1875 stated: "By this simple means signals have been sent [by
wire] for long distances, as from Mr. Edison's laboratory to his dwelling house in another part of the
town. Mr. Edison states that signals have also been sent the distance of 75 miles on an open circuit,
by attaching a conducting wire to the "Western Union telegraph line."
As It Developed. A "black box," used by Edison to demonstrate etheric force was sent to Paris where
Edison's assistant, Charles Batchelor, lectured on the etheric force. (The black box detector consisted
of a pair of adjustable graphite points in a shaded enclosure, with terminals to attach it to an external
circuit.) There is a bare possibility that Heinrich Hertz might have heard about Edison's experiments,
for hi spark points with the micrometer adjustment are virtually identical to those in the black box,
and he repeated the experiment of turning the wire back upon itself.
Thomas A. Edison, from a print dated 1877, about the time he was
working on his "etheric force" invention. This and other illustrations in this article are adapted from
those appearing in "Menlo Park Reminiscences," Vol. I, by F. Jehl, Edison Institute, Dearborn Park,
Work on the telephone took Edison's attention away from etheric force for some time. But in 1885
he applied for a patent for a wireless telegraph system based on his etheric force. The patent drawings
show towers that are easily recognizable as radio masts, and two ships with broad ribbon-like antennas
hung between their masts! The text of the patent application goes into detail about the equipment shown
in the drawings.
"The wire (from the 'condensing surface' C) extends through an electromotograph telephone receiver
D (Fig. 2) or other suitable receiver, and also includes the secondary circuit of an induction coil
F. In the primary of this coil is a battery b and a revolving circuit-breaker G. This circuit-breaker
... is short-circuited normally by a backpoint key K, by depressing which ... the circuit-breaker makes
and breaks the primary circuit of the induction coil with great rapidity," Edison wrote.
the phenomenon as he saw it, Edison went on to state: "These electric impulses are transmitted inductively
to the elevated condensing surface at the distant point ... "
Here is where the confusion in
language occurred. At the time, the term induction, unless otherwise explained, meant electrostatic
induction (a tendency that still lingers on in some elementary physics textbooks). The transformer had
just been invented, and magnetic induction was a laboratory curiosity. The term "electrostatic" drifted
into obscurity as the art progressed, and later writers referring to the "induction telegraph" unquestioningly
accepted the term to mean magnetic induction.
The confusion was increased because the only commercial
use Edison made of his invention was the "grasshopper telegraph," a system of telegraphing from moving
trains to the telegraph wires alongside the tracks. This was a distance that could be covered easily
by electromagnetic induction, and historians who believe that radio communication started with Tesla,
Lodge, and Marconi assumed that this was the case. Yet, in explaining the "grasshopper telegraph" to
a reporter, Edison said, "The system works by electrostatic induction."
So, a change in the
generally accepted meaning of a word with the changing times buried the fact that Edison invented, described,
patented, and operated a radiotelegraph system in 1886 - a year before Hertz explained the cause of
the etheric force, which he called electric force.
What other "firsts" .may lay buried or attributed
to other discoverers because semantics denied the original inventor or discoverer his due? At least
now Thomas Alva Edison's long list of achievements will have numbered among them the discovery of radio
waves - even if he did not title them as such.
Editor's Note: We are given to understand that
the graphic-points "black box" is still in existence and has been exhibited on the second floor of the
restored Edison Laboratory.
In his book, "Menlo Park Reminiscences" (now believed to be out
of print and unobtainable), author Jehl says that Edison was intrigued by the spark and performed many
experiments to seek an explanation of its nature. Edison did find that the spark was unpolarized; had
no respect for the usual types of insulation; would not discharge a Leyden jar; and had no effect on
Unquestionably, Edison had stumbled onto radio-wave transmission, but the fact that energy could
be propagated through the atmosphere and not via wires was alien to all of his telegraphy experiments.
Posted September 15, 2011