astronomers thought the prominences are mountains, others held that they are flames, while others again were in favour of the theory that they are clouds.

It is the peculiarity of the spectroscope that it resolves in a moment questions to which other modes of research might be applied for years ineffectually. During the great eclipse of August, 1868, the powers of the new instrument were applied for the first time to the problem presented by the prominences, and in a moment, the mere apparition of a few bright lines as the prominence-spectrum shewed that these objects are enormous masses of glowing vapour.

I pass over the interesting series of researches by which Lockyer and Janssen independently found that the prominence-spectra can be examined when the sun is not eclipsed; and Huggins shewed that the prominences themselves can be rendered visible by aid of the spectroscope. It remains only that I should consider the perplexing evidence obtained respecting the corona (or crown of glory surrounding the eclipsed sun) during the total eclipse of last August, and the probability that during the eclipse visible in southern Europe towards the close of the present year, the difficult problem presented by the corona may be satisfactorily solved.

It had been noticed during the eclipse of August, 1868, that the spectrum of the corona seemed to be continuous; but some doubt existed whether the absence of dark lines might not be due to the circumstance, that in order to render the spectrum of so faint a light visible at all, it was necessary to use a wider slit than that used (as before described) when the Fraunhofer lines are to be shewn. During the eclipse of August 7th, 1869, it seems to have been placed beyond a doubt, however, that the spectrum of the corona is continuous-in other words, that it resembles the spectrum of an incandescent body! Some observers detected three bright lines superposed on this continuous spectrum; and these bright lines would indicate, according to what has already been shewn, that the source of light to which they are due is a glowing gas!

Now can we believe that the solar corona consists of incandescent solid or fluid substances mixed up with certain glowing gases? Whether we regard the corona as in reality a solar appendage, or as merely an optical appearance, we seem alike forced to abandon an hypothesis so bizarre and fanciful.

Now Mr. Lockyer by comparing his own observations of the prominencespectra with researches carried on by Dr. Frankland, the eminent physicist, has come to the conclusion that the true solar atmosphere cannot extend very far, relatively, from the solar photosphere itself. The gases which produce the bright lines in the prominence-spectra certainly do not exist, he says, at the enormous pressure due to an atmosphere corresponding in

* At the lecture the subjects here touched on were dealt with at length, and illustrated with illuminated photographs; but the readers of this magazine have already had an account of these matters in my paper on the sun-Monthly Packet, January last.

height to the extent indicated by the corona. Indeed, independently of all such observations, we must obviously dismiss the thought that the corona is a solar atmosphere, since its extent is such that were it an atmosphere round the sun, and subjected therefore to the sun's tremendous attractive energies, it would be absolutely liquified if not solidified by the enormous resulting pressure.

But can we accept the theory that the corona is not a solar appendage at all that it is due, as Mr. Lockyer says, to the glare of our own atmosphere? Here I must admit I am wholly at issue with Mr. Lockyer. To establish the theory that the corona is due to atmospheric glare, we must shew how that glare is occasioned. If the air which lies where we see glare is really illuminated, that theory is in some sense justified. But during a total eclipse, the air which lies in the direction of the eclipsed sun, or within many degrees of that direction, is in absolute darkness. The shadow of the moon is in some eclipses two or three hundred miles or more in diameter, so that the air all round the observer is in shadow. What we ought to see then, if only the sun, the moon, and our own air, were in question, is a black space all round the sun, and only at a distance of several degrees from his orb the faint beginning of atmospheric glare. There should be, in fact, a negative corona around the sun, and one far wider in extent than that positive crown of glory which surrounds his eclipsed globe.

And if we consider the matter rightly, we shall see that the very blackness of the moon's disc, on the heart of the corona, is a proof that the light comes from beyond our satellite. If the air were illuminated as supposed, why should the illumination just stop short of the disc of an object which lies far beyond our atmosphere?

For these reasons, and others on which I need not now enter, I believe (in common with many other students of astronomy) that the corona is a solar appendage,—or rather, I hold that there can be no doubt whatever on the point.

At the same time I fully agree with Mr. Lockyer in believing that the corona is not a solar atmosphere. On this point also there can be no reasonable doubt.

What then is the corona?

It may seem rash to venture a theory where the evidence we have is as yet incomplete, and still more so, when there is a prospect of a speedy answer to our inquiries. Still I believe that the very difficulties I have dwelt upon serve to render the task of theorizing more easy. For certain hypotheses, which might otherwise attract our attention, are put out of the field altogether.

I think there is good reason for believing that the corona is simply a region filled with meteoric particles, each travelling on its own orbit, and therefore necessarily with enormous velocity around the sun. We know

quite certainly that there exist vast numbers not merely of meteors but of meteor-systems, circling around the central luminary of our system.

It has been shewn by the researches of Leverrier that the united mass of these bodies, within the orbit of Mercury, is such as appreciably to affect the motions of that planet. It has further been shewn by Mr. Baxendell, the eminent meteorologist, that certain weather-changes exhibit in the clearest manner the fact that a system of bodies must exist where Leverrier places his zone of small planets or cosmical particles. Such a system, placed in the full blaze of the sun's light, could not fail to become visible during a total eclipse; and the corona presents precisely such an appearance as we might look for in a system of the sort.

It remains, however, that the spectroscopic analysis of the corona's light should be explained. A system of bodies reflecting solar light would exhibit a spectrum like the sun's. We have seen that the coronal spectrum differs from the sun's at once in having no dark lines and in shewing certain bright lines.

I believe the explanation of the coronal spectrum is to be found in the position of the bright lines. These lines are the same as those which appear in the spectrum of the Aurora Borealis. Now we know that this phenomenon is associated with the earth's magnetic action; and it has been suggested, with much appearance of reason, that the auroral light indicates the occurrence of electrical discharges in the upper regions of the air. This being so, we are led to recognize that portion of the coronal light to which the bright lines are due, as arising from the passage of electrical discharges between the components of the meteoric ring forming the corona. To the same cause we may attribute the continuity of the coronal spectrum, since the electric discharge would in all probability exhibit (but less brightly) other coloured lines, filling up the gaps in the spectrum due to the reflection of the solar light from the meteoric particles.

It is most probable, however, that the observations to be made with the spectroscope during the eclipse of December next will place us in a better position for theorizing on the physical condition of the

corona.

In conclusion, let me remark that I have scarcely touched on a tithe of the observations of interest which have been made by means of the most powerful instrument of scientific research yet placed in man's hands. Spectroscopic analysis is indeed only in its youth; but already it has done so much, that not one lecture, but a course of lectures, would be needed to do it justice. I shall, however, have attained the end I have chiefly had in view, if any of my hearers should be invited to study for themselves, closely and consecutively, the wondrous teachings of the spectroscope as used by our leading physicists.

THE PILLARS OF THE HOUSE;

OR,

UNDER WODE, UNDER RODE.

CHAPTER V.

WORKING FOR BREAD.

'Parson's lass 'ant nowt, an' she weant 'a nowt when 'e's dead;
Mun be a guvness or summat, an' addle her bread.'

Tennyson.

'TELL, little one,' said Mr. Rugg, the doctor, as he found Geraldine on the landing-place outside her mother's room, and spoke to her in a voice that to her reluctant ears, as well as to those of Sister Constance who followed him, sounded all the more vulgar because it was low, wheedling, and confidential; 'you are always about the house, you know everything —what accident has your mamma met with?'

Cherry's face grew set.

'She has, then,' said the doctor, looking at Sister Constance. 'I thought so. Now, be a good child, and tell us all about it.'

'I cannot,' she said.

Come, don't be silly and sulk. No one will punish you; we know it was an accident; out with it.'

'My dear,' said Sister Constance, 'this is a pity. Much may depend on your speaking.'

Cherry began to cry very piteously, though still silently.

'Yes, yes, we see you are sorry,' said Mr. Rugg, but there's nothing for it now but to let us hear the truth.'

She shook her head violently, and brow and neck turned crimson. Mr. Rugg grew angered, and tried a sharper tone. 'Miss Geraldine, this is regular naughtiness. Let me hear directly.'

The flush became purple, and something like 'I won't' came from behind the handkerchief.

'Leave her to me, if you please,' said Sister Constance gently; 'I think she will tell me what is right to be told.'

'As you please, Lady Somerville,' said Mr. Rugg, who, since he had discovered her title, was always barbarously misusing it; but the thing must be told. It is doing Mrs. Underwood a serious injury to let childish naughtiness conceal the truth.'

Constance put her arm round the little girl, a tiny weight for thirteen years old, and took her into the room where she had last seen her father. She was sobbing violently, not without passion, and the more distressingly because she carefully stifled every sound, and the poor

little frame seemed as if it would be rent to pieces. 'Cherry, dear child, don't,' said Constance, sitting down and gathering her into her arms; 'do try and calm yourself, and think—'

'He-he-I won't tell him!' sobbed the child. 'He's a bad manhe tells stories. He said he would not hurt me-when he knew he should most terribly. Papa said it was very wrong. Papa was quite angry-he called it deceiving, he did! I won't tell him!'

'My dear child, is there anything to tell? think about what is good for

your mother.'

Don't think about him,

'She told me not,' sobbed Cherry, but not with the anger there had been before. 'No, no, don't ask me, she told me not.'

"Your mother? My dear little girl, whatever it is, you ought to say it. Your dear mother seems to be too ill and confused to recollect everything herself, and if it is not known whether she has been hurt, how can anything be done for her?'

Cherry sat upon her friend's lap, and with a very heaving chest said, 'If Felix says I ought-then I will. Papa said we should mind Felixlike him.'

'I will call Felix,' said Sister Constance.

Mr. Rugg looked very impatient of the delay; but Felix, who had just come in to dinner, was summoned. standing by Geraldine's chair.

་

He came at once, and was soon

to tell,' he said, as the loyal little What did happen?'

'It was on the day after New Year's Day,' said Geraldine, now speaking very fast. 'You were all at church, and she came out ofthis room with Bernard in her arms-and called to me that I might come and sit with-him, because she was going down to the kitchen to make some beef-tea. And just then she put her foot into a loop of whip-cord, and fell. She could not save herself at all, because of

Bernard; but she went backwards-against the steps.'

'Did she seem hurt at the time?'

'I did not think so. She pulled herself up by the baluster before I could get up to help her, and she never let Bernard go all the time-he did not even scream. She only said, "Now mind, Cherry, do not say one word of this to Papa or anybody else," and she told me she wasn't hurt. Oh! was she really?' as the Sister left the room.

'I wonder whose the string was,' said Felix vindictively.

'Oh, never mind! He'll be so sorry! Oh! I hope she won't be very much vexed at my telling!'

'She will not mind now,' said Felix; 'it was only not to frighten Papa.'

And Felix had his little sister in that one position where she felt a sort of comfort-like a baby in his arms to be rocked-when Sister Constance returned with the doctor. He spoke without either the anger or the persuasive tone now, and Cherry could bear it better,