to M axwell’s theory. The model illustrates very clearly the
phenomena attendant on the discharge o f a Leyden jar, showing
the residual charge and the conditions under which the discharge
becomes either oscillatory or uni-directional. In a later paper,
which involved him in a correspondence w ith Avenarius, he
extended the properties o f the model to include therm o
electric phenomena. In his Modern Views of
, published
in book form in 1889, instructive use was made o f models
conceived by him to illustrate the properties o f electric systems.
Lodge was, indeed, the child o f an age which rejoiced in the
explanation o f physical processes by means o f mechanical models;
like his great predecessor, Maxwell, he knew when a model had
served its purpose. But the concept o f the ether o f space dominated
his whole working life. In his youth as a physicist he was well in
the forefront o f the science o f his day, following in the steps o f
Faraday and Maxwell by concentrating attention on the properties
o f the medium surrounding electrified bodies. The functions o f
that medium interested him deeply and his work did much to
stimulate interest in its properties. Fifty years ago he wrote in the
preface o f his book, T ew things in physical science appear to me
more certain than that which has so long been called electricity
is a form, or rather a mode, o f manifestation o f the ether.’ It is
not too much to say that through seventy years o f an active
working life he remained faithful to his creed—an almost
sality and overwhelm-
en jar discharge was
well known and had been demonstrated in various ways long
before G. F. FitzGerald, whom Lodge first met in 1878, in Dublin,
had discussed with him the possibility o f producing Maxwell’s
waves artificially. FitzGerald described in 1883 how, by using
alternating currents, ‘it would be possible to produce waves o f
as little as ten metre wave-length, or even less’. Lodge began a
series o f experiments on electric waves travelling along wires in
the early ’eighties, and demonstrated their effects before the
Physical Society in 1888. He proved that oscillating pulses
OLIVER JOSEPH LODGE
557
passionate, though reasoned, belief in the ]
ing importance o f the luminiferous ether.
The oscillatory character o f the Ley
OBITUARY NOTICES
travelled along wires and were true waves which, by reflection,
were converted into stationary waves represented by a glow at
the central segment o f each pulse and were dark at the nodes. He
calculated the length o f the waves and emphasized the importance
o f his discovery from the point o f view o f the verification o f
Maxwell’s theory o f the nature o f light.
In the same year H ertz’s discovery o f such ether waves in space
was announced, and their reflection so as to form nodes and loops
was described. Lodge had thought that it was necessary to guide
the waves along wires in order to detect their presence, but
Hertz showed that they travel through free space and could
produce sparks in the gap o f a broken hoop o f wire o f appropriate
length at a distance from a sparking coil.
Both Lodge’s and H ertz’s experiments were verifications o f
Maxwell’s theory, but Lodge himself realized that there was a
great difference between the observations from a practical point
o f view and in 1889 he gave a demonstration o f Hertzian waves
at the R oyal Institution. He continued his experiments and
devised a coherer method o f detecting such waves. In 1890 he
described in Nature his Syntonic Leyden Jar experiment, which
was the foundation o f tuning and wave measurement, and in
1894, a few months after the death o f Hertz, using a coherer
method o f detection and a Branly tube, he gave a full
demonstration o f the physical properties o f Hertzian waves. In
August o f the same year, at the O xford meeting o f the British
Association, he gave the first public demonstration that the waves
could be used for telegraphic signalling in the Morse code, the
messages being sent and received through two internal and one
external stone wall over a distance o f sixty yards. His original
researches on electro-magnetic radiation and the relations between
matter and ether were summarized in a statement included in the
annual address o f the President o f the Royal Society in 1898,
when he was awarded the R um ford Medal o f the Society.
Lodge possessed none o f the arts o f the advertiser, and had
little interest in claims for priority. It is scarcely realized, even
to-day, outside specialist circles, how profound was his influence
558
on the early development o f wireless telegraphy, and how he
anticipated much o f the later short-wave methods; some o f the
forms o f coherer devised by him are prototypes o f the crystal
detector o f later years.
His mental pictures o f physical processes were always lucid
and served to guide his work in the right direction. In his Royal
Institution lecture o f 1894 he laid down conditions o f fundamental
importance concerning the weakness or strength o f a radiating
circuit and the properties o f a persistent vibrator. He saw clearly
that the inherent defect o f the Hertzian oscillator was its heavy
damping and that in such circumstances selective tuning was
impossible. The expression for the damping points the way to
the cure—an increase in the inductance o f the system—and this
remedy was one o f the prominent features o f his great patent
o f 1897, a specification which, more than anything else, made
spark-telegraphy possible.
It has already been mentioned that Lodge’s first introduction
to physics was a course o f six lectures on heat given by Tyndall
at the Royal Institution and afterwards published in
as a
Mode of Motion. Lodge was fascinated by Tyndall’s experiments
and style o f exposition, and these and other lectures and Friday
evening discourses at the Institution had a great influence upon
his life. He was thus introduced to a new world by a lecturer who
possessed great gifts o f stimulating interest in it by impressive
words and striking experiments.
Lodge himself had remarkable capacity for expressing scientific
facts and ideas simply and clearly in speech and in writing. In
conversational style, whether in a lecture or discussion, he
presented the essential points o f his subject naturally and with
such enlightened insight that he always made close and friendly
contact w ith the minds o f those addressed by him. This was as
true whether he was addressing a scientific audience on new
advances or conceptions, or was giving an evening discourse to a
general assembly at a meeting o f the British Association. He was
always a welcome speaker at such meetings, because he always
said in his pleasing and sonorous voice something worth
OLIVER JOSEPH LODGE
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