STRANGE NEWS ABOUT THE SOLAR PROMINENCES. 
45 
subject of solar research assumed a new aspect. Since that 
day the progress of discovery has been so rapid as to render it 
difficult to believe that the method was first applied only three 
years ago. 
Passing over the first observations of Janssen, Lockyer, 
Capt. J. Herschel, and Secchi, and giving less attention to the 
questions of the condition of the prominences as respects tem- 
perature and pressure than to the motions of the prominence 
matter, we find in the work of Zollner and Respighi the first 
clear intimations of the wonderful activity of the glowing va- 
pours surrounding the sun’s globe. So far back as the spring 
of 1869, Zollner recognised the action of solar repulsive forces 
— which he regarded and still regards as eruptive — in casting 
forth enormous masses of glowing hydrogen. In several papers 
he has discussed the evidence he has obtained respecting the 
energy of these forces, arriving at conclusions which were re- 
garded at the time as startling in the extreme, but must now 
be considered as falling far short of the reality. He assigned 
120 miles per second as the probable velocity of outrush in 
solar eruptions, and spoke of eighty or ninety thousand miles 
as the probable limit of height to which the erupted matter 
attains before, gradually descending, it spreads itself into the 
strange forms constituting the cloud-like as distinguished from 
the eruptive prominences. 
Respighi was led to regard the repulsive action of the sun 
as electrical in origin ; but as he agrees with Zollner in regard- 
ing the prominences as solar eruptions, it is a matter of 
comparatively small importance that he considers the force 
producing the eruptions as something very different in its 
nature from the volcanic action believed in by Zollner. At 
the present stage of our progress it is much more important to 
determine the extent and energy of the solar eruptions than 
the cause or causes to which they may be due. Respighi gave 
the following account of the appearances presented by the 
prominences. It is important that his description should be 
carefully attended to, as it supplies independent evidence of 
some of the remarkable observations made by Father Secchi. 
44 When there are faculce on the sun there are usually pro- 
minences ; but over the sunspots themselves, though there are 
low jets, there are no high prominences. As respects the dis- 
tribution of prominences round the sun’s limb, it is to be 
noticed that great prominences are never recognised in the 
circumpolar solar regions, and the prominences actually seen, 
besides being small, are few in number, and last but a short 
time. At the solar equator the prominences are less frequent, 
less active, and less developed than in higher solar latitudes.” 
He found that 64 the formation of a prominence is usually pre- 
ceded by the appearance of a rectilinear jet, either vertical or 
