168
DOC. 38 ETHER AND RELATIVITY
10
SIDELIGHTS
ON
RELATIVITY
relation to each
other; it
was
also at vari-
ance
with
the result
of
Fizeau’s
important
experiment on
the
velocity
of
the
propaga-
tion
of light
in
moving
fluids,
and
with
[9]
other
established
experimental
results.
[10]
Such
was
the
state
of
things
when H.
A.
Lorentz
entered
upon
the
scene.
He
brought
theory
into
harmony
with
experience
by
means
of
a
wonderful
simplification
of
theoretical
principles.
He achieved
this,
the
most
important
advance in
the
theory
of
electricity
since
Maxwell,
by taking
from
ether its
mechanical,
and
from matter
its
electromagnetic
qualities.
As
in
empty
space,
so
too in
the interior
of
material
bodies,
the
ether,
and
not matter viewed
atomistically,
was
exclusively
the
seat
of
electromagnetic
fields.
According
to
Lorentz
the
elementary particles
of
matter
alone
are capable
of
carrying
out
move-
ments;
their
electromagnetic
activity
is
entirely
confined
to
the
carrying
of electric
charges.
Thus Lorentz succeeded in
re-
ducing
all
electromagnetic happenings
to
Maxwell’s
equations
for free
space.
As
to
the
mechanical nature
of
the