or lecture demonstration. Tw o o f his sons, however, took up
the subject o f electrical fume-deposition which is now a great
industrial system. It was upon the fundamental research and
pioneer experiments o f Lodge, followed by the w ork o f D r F. G.
Cottrell in the U.S.A., and D r Moeller in Germany, that these
remarkable developments are based. Lodge’s early experiments
illustrated how fog might be dispersed by electrostatic means.
Their practical applications are in the abatement o f the dust
nuisance from power stations and other works, the collection o f
valuable material from the effluent gases in smelting and refining
operations, and the cleaning o f gases from blast furnaces and
coke-ovens for subsequent use. Many thousands o f industrial
works are now equipped w ith installations for electrostatic
precipitation with systems which had their origin in Lodge’s
laboratory experiments.
Lodge did not embark on his career as an experimenter at
quite such an early age as did Maxwell, but at eighteen he had
set up a laboratory equipped w ith primitive apparatus, and with
that remarkable and characteristic product o f its age, the Penny
Cyclopaedia, as a book o f reference. He made for himself the
discovery that an electric circuit possesses self-induction, a
property analogous to inertia, and devised a means o f measuring
it. The property was not unfamiliar to physicists, though its
significance was not fully appreciated. To Lodge, self-induction
was a fertile field o f experiment, and he pressed the idea into
service in many directions, introducing it into the ignition o f
motor-cars, the phenomena o f lightning and lightning-conductors,
and ultimately the tuning o f electric waves.
The high-tension electric ignition system, which two o f
Lodge’s sons applied to internal combustion engines, in the
form o f induction coils producing oscillatory sparks o f high
frequency, was developed from his experiments on electric
discharges derived from Leyden jars and their relation to
lightning discharges. There was nothing entirely new in the
experiments, but it was Lodge who gave particular attention to
the sudden rush along uninsulated conductors when insulated
OLIVER JOSEPH LODGE
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OBITUARY NOTICES
Leyden jars were discharged. The whole disruptive discharge
occurs impulsively in a small fraction o f a second, and as it
can be produced between terminals under water or in any sort
o f oily mixture its application to spark ignition has proved
industrially valuable.
The question o f the relative m otion o f ether and m atter was
rapidly coming to the fore during Lodge’s middle years. The
simple explanation o f the aberration experiment w ith an ‘em pty’
telescope pointed to a stagnant ether; the experiments o f Airy
and Hoek, which show that the aberration is the same whether
a telescope be filled w ith air or water, may be interpreted in
terms o f a convective drag involving a coefficient (/u,2— 1) /yu,2.
This law o f drift had been verified by Fizeau and, later, by
Michelson and Morley, who repeated Fizeau’s experiment under
greatly improved conditions.
But the celebrated experiment known,
, as the
Michelson-Morley experiment, pointed directly, in the view o f
the physics o f the time, to a convected ether, and Lodge’s in
vestigation o f the effect o f moving matter on the velocity o f light
was a contribution o f major importance to the subject.
The experiment was, for its day, on the heroic scale—it was no
small feat to m ount a pair o f steel discs, each a yard in diameter,
w ith their planes parallel and separated by about an inch, in
such a manner that they could be spun round a vertical axis
at as high a speed (3000 r.p.m.) as was consistent with their not
bursting under stress.
A beam o f parallel light was divided by means o f a half-
silvered m irror so that the two resulting beams were reflected
by four fixed mirrors and traversed the space between the discs
several times before interfering to produce fringes; the path length
between the discs was in the neighbourhood ol forty feet.
Again, it was no easy matter to get rid o f spurious effects—
that due to air blast from the discs being specially pronounced
—but when all sources o f disturbance had been eliminated no
measurable shift o f the fringes was seen.
Michelson and Morley had given what seemed to the minds
5 6 4
o f the day a clear-cut answer to an im portant question; Lodge’s
experiment re-opened that question.
In a later paper Lodge described similar experiments dealing
w ith the influence o f mass, magnetization and electrification by
spinning at the same high speeds ‘an oblate spheroid o f best
Swedish iron, a yard in diameter and half a foot thick, w ith a
deep channel or groove half an inch wide cut into its rim to a
depth o f one foot all round’. The mass o f the spheroid was a little
short o f three-quarters o f a ton. In all the experiments, though a
shift o f the central band by so little as a hundredth o f its width
was observable, the results o f all the experiments were negative.
Just before leaving Liverpool, Lodge published, in collaboration
w ith R . T. Glazebrook the result o f a series o f experiments on
the determination o f V’ by measuring an inductance, a capacitance,
and the period o f oscillation o f the discharge o f the circuit made
up o f these constituents. The experiment was an interesting one,
though the value o f V’ (3-009 X io 10 cm. per sec.) was not o f the
highest order o f accuracy. Indeed, the authors did not view the
paper ‘as one describing a very exact method o f determining
V’, but rather as a study in the oscillatory discharge o f a con
denser which incidentally leads to a determination o f V’ by a
novel m ethod’.
In his early days at University College, Liverpool, Lodge
carried out some experiments on thought transference and was
assured by them o f the reality o f this phenomenon, to which the
name o f telepathy was given. About the same time, the Society
for Psychical Research was founded and Lodge’s experiments
were recorded in the proceedings o f the Society. The object
o f the Society was- to investigate obscure human faculties
and Henry Sidgwick was the first president. F. W . H. Myers
was the chief leader in this field o f enquiry and he held that if,
as in telepathy, mind could act on mind without physical contact,
it might survive without the use o f the body.
Lodge was convinced o f the truth o f survival through experi
ments made with Mrs Piper, o f Boston, who was brought to the
notice o f British psychical researchers by Professor William James
OLIVER JOSEPH LODGE
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