DOC.
119
SEPTEMBER
1908 85
enclosing a
photograph
of
one
of
my radiograms[2]
from which
you
will
immediately
recognize
the
superiority
of
my
method,
i.e.,
if
you
have
seen
Kaufmann's
radiograms.
Kaufmann
has
a
great
many sources
of
error
in his
experimental setup,
and
I have
already
told him
about
one
of
them.
Already
the
asymmetry
that
I
discovered
in
the
two
branches of the
curve,
\
which should be
symmetrical according
to
the
theory
of
the
experimental setup, is
by
itself
sufficient
to
render the
claim to
precision
illusory.[3]
At
my suggestion,
Kaufmann measured the
asymmetry,
and
he
found
an
asymmetry
of
5% in
two
of
6
curves!
That
is
almost
what
the difference in the
theory
that
has to be
tested
comes
to.
There
are,
in addition,
many
other
oversights,
etc.[4]
As
regards
the
ratio of
e
to
m0,
the
theory applied
in the
calculation
of
the
velocity,
first
by
Schuster[5]
Ģ
and
then
by
Kaufmann
and
Simon,
is
wrong,
and
the results for

are
completely
m0
illusory.
The
term
for the
energy
of
the
Roentgen
rays
is
missing
from
the
righthand
side
of
the
equation[8] eV=1~2
my2.
For
just
as
yrays
emanate
from
radium
salts,
they
also emanate from
wherever
/3rays
are being
produced,
and thus also from
the cathode
and its
vicinity,
in
short
from
wherever electrons
are
being
accelerated.[9]
The
omission
c of
the
Roentgen
energy
makes
u,
and thus also
,
too
large.
I
recently
learned of
m0
M
exceedingly
precise measurements
by
Schuster's method that
yielded
1.78
·
10
.
These
measurements
will
probably
be
published
soon.[10] Shortly
I
am
myself going
to
determine
experimentally
the
percentage
of
the
Roentgenray energy
and correct
accordingly
the
values for

yielded
by
the old
Schuster method.
m0
Concerning
your
arguments
about the
concept
of
force,
I
understand
very
well
that
you
prefer to sidestep
this
concept
completely.
But the
debate
with Mr.
Cunningham
forces
me
to
get
into this
question.[11]
In
fact,
one can
base
oneself
completely
on
the
theory
of
relativity
and
ask,
for the
purpose
of
experimental investigation,
what
force acts
upon
an
electron that
moves
in
a
uniform
magnetic
field H, and
then make
the
mu
2
provisional
assumption,
=
eHu sin
a,
where,
according
to
your theory
and
Lorentz's
theory,
one
has
to
set
m
=
m0(
1/32)
2. Now, Cunningham
claims
that
the
TT
force
is
ĢHu
sin
a
,
which
is
exactly
the
same
force
that
I
have
derived
from
my
own
1
ß2cos2a
relativity
principle,[13]
which I
myself
have
just
disproved by
experiment. I
would
now
like