( 169 ) 
pieces of the prominence not even taking any part in the enormous 
motion along the line of sight. 
The above-given explanation of the phenomenon by anomalous 
dispersion solves all these mysteries. 
It occurs very seldom that prominences show a rapid sideward 
motion, i.e. a motion in the meridian of the Sun. FÉNyr mentions as 
an exceptional case a sideward velocity of 25 kilometers per sec’). 
As, on the other hand, velocities of 250 kilometers and more in 
the direction of the parallel (calculated after DorPrer) are by no 
means a great exception, we meet with contradictions — as is admitted 
also by FExy1 — from which it appears impossible to escape, unless 
we doubt the reality of the velocities. 
It is surprising and satisfactory to see how nearly all the pecu- 
liarities in the behaviour of prominences, as deseribed by Young, 
FÉNyr and many others, appear quite intelligible as soon as we look 
at these phenomena from our point of view. 
Let us choose only a few more examples out of the vast material. 
FéNyr says (le. p. 115): „/Schon seit Jahren habe ich bemerkt, 
dass helle hervortretende Punkte in der Chromosphäre, welche eine 
kleine Verschiebung gegen blau.zeigen, der Ort sind, wo alsogleich 
der Aufstieg einer Flamme oder einer kleinen Protuberanz erfolgt” 
Now the process of whirl-formation in a surface of discontinuity 
proceeds, as a rule, from the inner parts of the Sun outwards. In 
the axis of a whirl the density is a minimum. Consequently, at the 
moment the whirling reaches the apparent edge af the Sun, a mini- 
mum of density will be found just projecting beyond the edge. 
Here we have a place, where the density increases from the photo- 
sphere outward and where, therefore, the violet-facing component of 
the chromospheric double-line temporarily prevails: it seems as if a 
shifting towards the violet occurs. Shortly afterwards the more 
distant parts set a whirling and the prominence appears. 
In the description of a great prominence, observed by FENyr on 
the 18th of Aug. 1890, we read ia. the following particulars *): 
„Ein ganz besonderes Interesse verleihen dieser an und für sich 
schon grossartigen Erscheinung die Eigenbewegungen in der Gesichts- 
linie, die an derselben beobachtet wurden. Eine ungefähr zwischen 
40" und 50” Höhe liegende Schicht, (deren Lage in der beigegebenen 
Figur genau bezeichnet ist), zeigte eine heftige Bewegung gegen die 
Erde zu. Das rote Licht des Hydrogeniums ergoss sich daselbst in 
verworrenen Formen über den Spaltrand gegen blau hinaus ohne 
1) FéNy:, l. c. p. 114. 
2) Fenvi, |. c. p. 129. 
