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indessen den Spalt ganz zu verlassen. Die Bewegung war durchaus 
local, die Umgebung zeigte keine Spur einer Bewegung. Die Geschwin- 
digkeit derselben war keine ungewöhnlich grosse; ich erhielt aus 4 
mit dem Fadenmikrometer gemachten Messungen zwischen 11 h. 45 m. 
und 12 h. 15 m. verschiedene, zwischen 94 und 201 klm. schwan- 
kende Werthe. Was aber die Erscheinung zu einer besonders merk- 
würdigen gestaltet ist der Umstand dass, während diese in der Höhe 
vor sich gehende ganz locale Bewegung nicht einer Ausströmung 
zugeschrieben werden kann, dieselbe trotzdem doch eine halbe Stunde 
lang beobachtet wurde! Nehmen wir als Mittelwerth der Geschwin- 
digkeit 150 klm. per Secunde an, so hätte dieser bewegte Teil 
der Protuberanz während der zwischenzeit von 30 Minuten gegen 
270.000 klm. durchlaufen, also wohl auch den scheinbaren Ort 
ändern müssen.” 
Of course this contradiction immediately vanishes if we only 
suppose, that in the part of the prominence, showing the persistent 
shift of the hydrogen light towards the blue, the density of the solar 
matter was increasing in the direction from the photosphere outwards. 
This supposition is quite in harmony, too, with the fact, that the 
picture of this prominence shows very important whirling below the 
part in question and no disturbance worth mentioning above it. 
Observers have often been puzzled at the rapid disappearing of 
enormous prominences and at the perfect calm in the whole region, 
including the Sun’s surface, a short time after such a violent “erup- 
tion” had taken place. It was hardly conceivable that the ejected 
incandescent gases could loose their huge quantities of heat so rapidly, 
nor that the eruption had no further visible consequences. 
In our theory a large prominence is nothing but the visible token, 
that whirling is going on almost simultaneously over vast regions. 
The very important varieties of density in the whirling mass may, 
however, be annulled by displacements of much matter over relatively 
small distances, which process, of course, may go on without violent 
movements and yet be accomplished in a short time. So there is no 
reason whatever to expect, that a great prominence will leave the 
medium in a highly disturbed condition. 
Whosoever wishes to consider prominences as eruptions, must 
grant, that it is one of the most difficult problems to account both 
for the tremendous values of the ascending velocities sometimes observed 
and for the most capricious way, in which the speed often suddenly 
changes without any conceivable cause. The 20% of Sept. 1893 
FÉNyr witnessed a prominence ascending 500000 kilometers in a 
quarter of an hour, that is at an average velocity of more than 
— See ne Te =d 
