4 1 4 D O C U M E N T 4 2 1 J A N U A R Y 1 9 2 5
well be that the charge of a proton and electron is the same when statically mea-
sured, but dissimilar when electromagnetically measured. Thereby the terrestrial
and solar fields would naturally be explained, but not the meteorological phenom-
ena, which are anyway still obscure. Under these conditions it would be interesting
to observe directly the magnetic field generated by moving masses. Although this
effect is very small, its detection is not entirely without prospect. I haven’t yet made
any precise calculations yet because this thought only occurred to me today; nev-
ertheless, I would like to submit to you the underlying arguments:
I let a mass of, e.g., 10 kg lead fall from a greater height (15 to 50 m). The lead
is connected to the ground by a thin wire; then, electromagnetically measured, it
represents a load of 1 electr. stat. unit = coulombs. During its fall it produc-
es a surge of amps, here, at a fixed point near its path during about
secs. This current has a huge electromotive force. In order to brake the fall of the
piece of lead within a few dm, one needs
109
dyn, which would be equivalent to a
field of
109
electrostatic units. Our current therefore has an electromotive force of
3·1011
volts!
Now I let the lead fall through a Rowland ring, which corresponds to half a coil.
A magnetomotive force of forms within the iron, as well as a correspond-
ing magnetization, independent of the iron’s cross section. Now I wrap around the
iron a secondary coil of about 100 windings of a fine wire of as low capacity as pos-
sible. This coil is connected to a vacuum tube which, if necessary, can be succeeded
by more. I am hoping that after suitable amplification an electrometer or a tele-
phone can detect the current surge. However, I don’t yet have much experience us-
ing the amplifier tubes of wireless telegraphy, so I can be mistaken in the estimate
of the attainable precision. If necessary, one can, of course, gain one or two deci-
mals by enlarging the dimensions of the piece of lead. With regard to the height,
about 15 m are available to me in the laboratory, furthermore a chimney outside the
laboratory of 50 m height.
I am, naturally, not going to begin with this research immediately. I would first
like to evaluate somewhat the prospect of success. It would therefore be very agree-
able to me to know your opinion on this question.
The construction of the expansion apparatus will still take some time. Because I
haven’t found a suitable boiler, I am going to order one like those made from iron
sheeting with autogenous soldering.
In great respect, sincerely yours,
A. Piccard.
1
3
109
⋅
---------------
1
3
107
⋅
---------------
1
100
---------
2π
3
107
⋅
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