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When Electronics was

Young (9)

Dear Editor — in the Novem-

ber 1999 issue of Elektor the

above interesting series has a

brief note on Guglielmo Mar-

coni that is misleading.

Marconi’s early experiments

were carried out in Italy not

England. He established that

communication using electro-

magnetic waves was possible

at the age of 20 experimenting

at his parent’s estate near

Bologna. He moved to England

as the Italian government

showed no interest in his

invention and his English moth-

er felt he would be more likely

to achieve success in her

mother country. At the time,

this country was a leading mar-

itime nation and there was no

means of communicating with

ships once they were out of

sight of land.

It was in England that Marconi

filed his patent applications,

supported by the chief engineer

of the Post office, Sir William

Preece.

To call Marconi a ‘physicist’ is

a gross insult. If he had been a

physicist, he would be unlike-

ly to have achieved transat-

lantic communication. The

physicists of the day held the

view that electromagnetic

waves travelled in straight lines

and were absorbed by land and

water. The curvature of the

earth created a 50 mile high

mountain of water across the

Atlantic Ocean so no waves

coild possibly reach the New

World. Marconi with no formal

education ignored the ‘experts’

and was successful. Neither

the physicists nor Marconi

knew about the existence of the

ionosphere which convenient-

ly reflected his waves from

Poldhu to St. Johns.

Beware of experts!

Guy Selby-Lowndes

the Encyclopaedia

Britannica, Marconi’s entry

reads ‘Italian physicist and

inventor of successful sys-

tem of radio telegraphy.

Received Nobel Prize for

Physics in 1909’. Similarly,

Chambers Dictionary of

Scientists lists Marconi as

‘Marconi, (Marquis),

Guglielmo, 1874-1937,

Italian physicist and engi-

neer, pioneer of radioteleg-

raphy’. In line with these

two renowned publica-

tions, I, too, have called

Marconi a physicist.”

”Owing to the shortness of

the article, I could not

include the fact that

Marconi had started his

experiments in Italy.

However, his main experiments

were carried out in England.

While still a physics student at

Leghorn technical school,

Marconi in 1894 demonstrated

the possibility of sending wire-

less signals over a distance of a

distance of some 150 metres at

his father’s estate near Bologna.

However, since he found nobody

in Italy interested in his experi-

ments, he and his Irish mother

travelled to England a year later.

There, in 1896, he demonstrated

a transmission of wireless sig-

nals over a distance of three

miles between Flatholm Island in

the Bristol Channel and Penarth.

He filed his first patent applica-

tion for wireless telegraphy at the

London Patent Office on 2nd

June 1896. In 1897, he transmit-

ted wireless signals over a dis-

tance of eight miles across the

Bristol Channel. This experiment

drew the attention of Sir William

Preece, the chief engineer of the

post office, as well as of the

Press. In 1899, he transmitted

Morse code across the English

Channel, which attracted atten-

tion from the Admiralty, resulting

in the installation of radio wire-

less equipment on Royal Naval

ships. In 1901, he transmitted

across the Atlantic from Cornwall

to Newfoundland. His pioneering

work was rewarded by the award

(shared) of the Nobel Prize for

Physics in 1909.”

”It is a debatable point whether

or not Marconi or his fellow

physicists and engineers knew

about the ionosphere. Michael

Faraday’s experiments in the

1840s and 1850s demonstrated

a clear connection between

magnetism and electricity.

Faraday’s friend and colleague,

James Clark Maxwell, confirmed

and explained Faraday’s experi-

mental results by a mathematical

theory. Maxwell’s calculations

showed that magnetic and elec-

tric fields affect each other, and

that light is a form of electro-

magnetic waves. Some tradition-

al physicists adhered to the

belief that light was a mechanical

phenomenon.”

”The conflict caused by

Maxwell’s hypothesis that elec-

tromagnetic waves are propagat-

ed at the speed of light lasted for

many years, until in 1888

Heinrich Hertz, Professor at the

Technical College in Karlsruhe,

finally closed the debate on the

wave character of light. He

demonstrated that the electric

sparks produced by him caused

electrical vibrations which were

propagated into space at the

speed of light.”

”During a cross-Atlantic trip,

Marconi had already noticed that

telegraph messages could be

received over distances of

up to 700 miles by day, but

at up to 2000 miles by

night. This discovery

prompted Oliver Heaviside,

an English physicist, and

Arthur Edwin Kennelly, an

American electrical engi-

neer, independently and

simultaneously to publish

their prediction of the exis-

tence of an electrically

conductive layer in the

upper atmosphere that

allows radio waves to fol-

low the earth’s curvature

instead of travelling in a

straight line as predicted

by a number of mathemati-

cians. The predictions of

Heaviside and Kennelly

were demonstrated in

1925 by Sir Edward Victor

Appleton, an English physicist

who, in 1947, was awarded the

Nobel Prize for Physics for his

contribution in the exploration of

the ionosphere”.

”Today, we know that the ionos-

phere is a region of the earth’s

atmosphere at a height of 30-

300 miles where short-wave

radiation from the sun partly ion-

izes gas molecules and atoms,

leaving them positively charged.

The ionized layers reflect short-

wavelength radiowaves, which

makes long-distance radio com-

munication possible. The ionos-

phere is layered according to the

concentration of free electrons,

called D and E layers (also called

the Heaviside or Kennelly layers,

depending on which side of the

Atlantic the term is used), which

result from molecular ionization,

and the upper layer, termed F

layer or Appleton layer, which

results from atomic ionization.

The thicknesses of the layers

vary with latitude, season, time

of day, and solar activity”.

”Since much of the research into

propagation was going on and

published while Marconi, Braun,

Slaby, and Arco, were conduct-

ing their experiments in England

and Germany, it is extremely like-

ly that they read about it.”

Our contributor replies as fol-

lows.

”Interpretation of certain aspects

of history can be contentious. In

Elektor Electronics

2/2000

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