D O C U M E N T 3 5 5 O C T O B E R 1 9 2 4 3 5 3
would have to be substantially greater than would be calculated from the drop in
the potential gradient with increasing
altitude.[3]
This is indeed the case; and I have
been racking my brains about it in vain, because this fact, already hinted at in older
measurements, has come out with quantitative certainty and surprising emphasis in
more recent observations by me and my collaborators. One naturally always does
first think of experimental errors, particularly those of principle in the measure-
ment methods used. That is why I have not pointed this out in my publications as
yet. If I now were to find a way toward an explanation from theoretical quarters,
that would be very welcome. I would be very grateful if you had the kindness to
send me the particulars.
In the interim I permit myself to relay to you the list below. These data by me
and my collaborators are already published; and I sent you the pertinent offprint at
the time: Physik. Z[eit]s[chrift] 22, [p.] 36,
1921[4]
(ion content measured during
balloon trips and aircraft ascents; a couple of minor corrections that still have to be
added do not yield any substantial modification to this problem; the final publica-
tion on this should be appearing imminently in the Annalen); Ann. d. Phys. 66, 261,
1921[5]
(potential gradients measured on balloon trips up to almost 9 km altitude).
1) Density of volume charge for a
cm3
in electrostat. un[its], calculated accord-
ing to the Poisson equation from the change in the potential gradient with altitude:
on the ground up to 2 m height
(Daunderer[6])
+1.10–7
in the balloon according to older data from 0 to 1,5 km height
1.10–9
″ ″ ″ ″ ″ ″ 1,5 ″ 1,5 ″ ″
0,2.10–9
″ ″ Everling & Wigand
[7]
″ 2,54 ″ 4,35 ″ ″
0,14.10–9
″ ″ ″ ″ ″ ″ 4,35 ″ 6,53 ″ ″ 0,11 ″
″ ″ ″ ″ ″ ″ 6,53 ″ 8,18 ″ ″ 0,037 ″
″ ″ ″ ″ ″ ″ 3,54 ″ 6,32 ″ ″ 0,14 ″
″ ″ ″ ″ ″ ″ 6,32 ″ 8,97 ″ ″ 0,035 ″
2) Density of volume charge for a
cm3
in el. stat. un[its], calculated as the dif-
ference (E+–E–) from the polar values for ion content E+ and E–. In the older mea-
surements, E+ and E– were not determined simultaneously and are therefore less
accurate than our newer measurements, for which two ion counters for E+ and E–
were mostly operated simultaneously. Furthermore, it should be noted that, in the
measurements at lower altitudes, larger ions (mist particles with a charge, Langevin
ions[8]
) are present in addition to the smaller ions caught inside the ion counters,
whose charge is not included in the magnitude (E+–E–). The real volume charge
must hence be substantially greater in these cases. This does not play a role at high-
er altitudes of the free atmosphere anymore.
At sea level, 0 above the sea, and at undisturbed land locations
according to many older data, in the mean about.................................
+1.10–7