SOLAR WONDERS.

Hawke's Bay Times, Volume 15, Issue 778, 14 April 1870, Page 4

SOLAR WONDERS.

j 4,stsonomers have fyeen revealing: go many wonders in the vast globe wbicty rules the planetary scheme, s}Lat we cannot yet hope to see the startling results of their researches co-ordinated into a consistent whole. Qn every hand new marvels are be ing brought to light. At one time 'Mr Lockyer surprises us by exhibiting the amazing velocities with which the solar storms rage across *he blazing surface of our luminary. 4.t another, the energetic astronomer who presides over the Roman Observatory tells us of water within ihe fierce tumult of the snots. The Kew observers track the strange influences of the planets on the solar atmosphere, watching not only the great tide of spots which sweeps in the ten-year period over the solar gtorm-zones, and then leaves oar sun clear from speck or stain, but also the ripples of spot-formation which pome in shorter periods, and seems inextricably blended to ordinary ob servers with the great periodic disturbances. Lastly, Lockyer, Huggins, Zollner, and Secchi describe the magic changes of form which pass over tongues of flame, projecting thousands of miles from the solar surface. We have before us' as we write a; series of colored prominence pictures taken by Br Zollner, the eminent phocometrician. It is impossible to contemplate these strange figures Without a sense of the magnificence pf the' problem whichHhe sun pre sents to astronomers. Here are vast entities—flames, if we will, but flames unlike all those with which we are familiar. And these vast tongues of fire assume forms which gpeak to us at once of the action of forces of the utmost violence and intensity. The very aspect of these pbjects at once teaches this, but it is the rapid changed of place and figure •jx> which the spots are subjected that are most significant on this point. Here is a vast cone-shaped flame, with a mushroom-shaped head of enormous proportions, the whole object standing 16,000 or 17,000 miles from the sun't' surface. In the cone figure we see the uprush of lately imprisoned gases, in the outspreading head the sudden diminution of pressure as these gases reach the rarer and upper atmosphere. But turn from this object to a series of six pictures placed beside it, and we see the solar forces in action. First, there is a vast flame, some 18,000 miles high, bowed towards the right, as though some fierce wind were blowing upon it. It extends in this direction some four or five thousand miles. The next picture represents the same object ten minutes later. The figure of the prominence has shaped mass, standing on a narrow alalk of light abo/e a row of flamehillocks. It is bowed towards the left, so that in those short minutes whole mass of the flame has swept thousands of miles away from its former position. Only two minutes later, and again a complete p.hange of appearance. The stalk and the flame hillocks have vanished, and the globe shaped mass has become elongated. Three minutes later, the shape of the prominence £as altered so completely that one pan hardly recognise it for. the same. The stalk is again visible, but the upper mass is bowed down on the right so that the whole figur? represents a gigantic A, without the cross bar, anal with the down stroke Abnormally thick. This great A is sometimes twenty thousand miles in height, and the whole masss of our earth might be, bowled within its legs without touching them ' Four minutes pass, and again the figure tas changed. The. flame-hillocks reawirr, the down-stroke of the A begins to ; raise itself from the sun's surface,' ' Lastly, after, yet another Interval' of four minutes, the figure c>f the prominence has lost all resemblance to'an A, and may now be Keened to a earners head looking towards the right.' TWwhole series of changes has occupied hut twentysree minutes, yejb the. flame exceeded atir earth in volume tenfold at the l^ast." But Mr has record--4\ an instance of a, yet more marvel}s!is nature. A vast prominence ex-

tending seventy or eighty thousand miles from the sun's surface vanished altogether in ten minutes. The very way in which drawings were taken savours of the marvellous. We have spoken of them as colored, They are ruby-redi, and so the pro minences appeared to the astronomer. The real light of the prominences is not ruby-red, however, but rose colored, with faint indications of pink, or even bluish tints. The fact is, that by the new method of observation the image of a prominence is formed by only a certain part of its light. We may say that out of several coloured images of the same prominence the astronomer selects one only for examination.

The explanation of this- is worthy considering, as it involves the essence of the method by which the prominences are seen at all. When we analyse light with a simple prism as Newton did, we get instead of a round spot of white —that is, mixed light—a row of overlapping spots of different color. It was only when a fine line of white light was was analysed, that one could detect the images of this line along certain parts of the rainbow-colored streak—. in other words, it was thus only that the dark lines of the spectrum could be seen. And it was to see these lines more clearly thai; the slit of the spectroscope was made so narrow and the rainbow-spectrum made so long by spectroscopists. But the observers of the prominences go back to the old method. If they used a narrow slit, a narrow strip of the prominence would alone form its spectrum, which would consist of a few bright lines. But by having a wide slit the whole prominence forms its spectrum, which consists of afew bright pictures of the prominences. There is a green picture corresponding to the spectral line called F, a red picture corresponding to the bright spectral lme called O, and so on. If the whole set of pictures were formed at once we could see none of them, for there would be side by side with them the blazing solar spectrum which would obliterate them altogether, just as in ordinary telescope observation the bright vmlight blots out the prominences from view. But if the observer uses such a battery of prisms that the solar spectrum would be very long indeed, and if he admits to view only that part of the spectrum opposite which one of the prominence-images exists,

he can then see that image quite distinctly, foi the neighboring part of the solar spectrum is so reduced in splendor that it no longer obliterates the prominence-figure. In this way, then, the observer selects one or other of the pictures of a prominence, either the red orthegreen picture, to examine. And strangely enough it is by no means certain that the two pictures are alike. Rather it is highly probable that they are different, though we have not space here either to indicate the reasons for believing this or to explain the circumstance should it eventually be established. It seems to us that when we consider the real dimensions of the solar globe, we appreciate more fully the wonderful nature of those processes of action- indicated by recent researches, than when we regard these without direct reference to the sun's magnitude. How many of us really appreciate the enormous volume of the sun 1 We read certain figures in books of astronomy, but do we grasp their full significance'? There is, however, a simple way of viewing the matter which at once opens our eyes to the vastness of the solar globe. If we remember that the earth on which we move so important, bears so minute a proportion to the sun, that if he were repre sented by a two-feet globe the earth would on the same scale appear no larger than a cherrystone, we see what wonderful processes of action those must be which are at work upon the solar surface. We recognise in our hurricanes the action of nature in her fiercest moods, but. the solar hurricanes would in an instant

destroy the whole globe on we live. We wonder at the volcano which lays a whole city in ashes, but our earth wo;ild be swept like a mote before the rgts.li of a solarvolcano. We see, lastly, in the

earthquake which upheaves a continent the most energetic of all the forces at work upon our earth, but the least of the throes which convulse the solar surface would toss a globe like ours as the waves of ocean toss the lightest sea-drift.