1898-99.| | MAGNETIC INFLUENCE OF SUN ON THE EARTH AND ON COMETS. 353 
The curve continued to show disturbance, and on March 2nd, when 
the volcanic area was central on the side of the sun opposite the earth, 
it is conceivable that it might exert the influence shown by the sharp 
dip, though I prefer to think this a recurrence of the slight February 
variation above alluded to. When the spot reappeared, it had changed 
its form so much that it seemed no longer the same. It had drifted a 
couple of degrees southward, and was evidently re-inforced by its original 
cause. Tacchini calls it a new spot. Whether it was so or not the 
eruption was still going on, for between March [5th and 17th the magnets 
were jerked about with unusual violence. It had not quieted down even 
during another rotation, for it made the instruments record its work, per- 
haps on coming into view, the 7th, but surely at centrality on April 
12th. All this while it had preserved its character as a double depres- 
sion—the two parts separating from each other more widely as their 
forces required more room for their display. The disturbed area was in 
the southern solar hemisphere, and not improbably therefore, in our 
spring, exerted a remarkable effect upon the earth. 
The solar eruption was accompanied by auroral displays, and the 
curve which shows their number and intensity in Canada is given on 
the same diagram, but inverted for convenience in printing. 
Facule are probably the crests of photospheric waves, raised by 
interior disturbances above the level of the solar atmosphere, and there- 
fore brighter in appearance than the general grey-yellow of the disc 
They seem to be, in a sense, the coverings of foci of impending outbursts, 
which may or may not be violent enough to cause spots, by breaking 
through the photospheric envelope. They accompany spots, and mag- 
netic effects are frequently noticeable when a faculous area becomes 
central. 
Some observers, accustomed to solar work, can see faculze almost 
clear across the disc. Prof. Hale, of Yerkes Observatory, has turned the 
camera’s photographic eye upon them, and has succeeded marvellously. 
It is to be hoped that at an early day regular observations may be 
taken, at least for a term, so as to be available in the-interest of magnet- 
ology. 
Like the prominence belts, facule gird the sun, in both hemispheres, 
with their wonderful flames, but, unlike the prominences, in sun-spot 
latitudes only. 
The fact that auroral displays accompany magnetic storms has long 
been known. Thus they also are an effect of the force which affects 
millions of square miles of the solar envelopes, and gives rise to spots. 
