"Still less should it bear the title of a book."

"In these pages, in fine, once upon a time, there was a somewhat piquant chapter entitled 'The Council of Ministers.' But somebody said to the author, Be careful, this is personality-these personages will be recognized: do not publish the chapter.' And the obedient author canceled the chapter accordingly. There was another chapter, entitled 'A dream of Love.' It was a rather tender love-scene, as a picture of passion ought to be in a romance. But somebody said to the author, It is not proper on your part to

bring out a book of which passion occupies so great a portion. This chapter is unnecessary; strike it out.' So the frightened author suppressed this chapter also. Once upon a time, too, in these pages were two morsels of verse. The one was a satire, the other an elegy. But somebody decreed that the satire was too pungent, and the elegy too melancholy. So the author gave them up, but this conviction she keeps, That a woman who sees the world ought to refrain from writing, since she may bring to the light nothing but what is perfectly insignificant."

Poor Delphine Gay! We know not whether " to love, honor, and obey," formed one of the promises of her marriage ceremony; the fulfilling it, however, seems to have been somewhat hard for her. Yet, when her ungrateful husband was in prison on account of his political views, she underwent all sorts of dangers for him. This sentimental poetess and lively novelist was certainly not a bad specimen of a wo[From London Society.

man.

ASTRONOMERS have seldom reaped a more abundant harvest of facts during a total eclipse (making hay, after their fashion, when the sun is not shining) than they did during the eclipse of December 12th last. To say that the anticipations which they had formed were amply fulfilled, would be to say far less than the truth. Although all hoped that important facts would be discovered, few expected so complete a success as has actually been achieved. Then, for the first time, the wonderful complexity and magnificence of the solar surroundings were clearly revealed.

Of the actual nature of that intensely hot and brilliant surface which the sun presents to our study, we can say but little. Astronomers are not certain even whether it is liquid or gaseous, and at present their ideas respecting the intensity of its heat are in most unsatisfactory disagreement. On the one hand, we have a theory by Father Secchi, the eminent Italian astronomer, according to which the heat of the sun's surface is certainly not less than ten

million degrees centigrade, or some eighteen million degrees of the common thermometer, (in which 180 degrees above freezing represents the heat of boiling water.) On the other hand, we have a theory maintained by Faye, St. Claire Deville, Fizeau, and many others, according to which the sun's heat does not greatly exceed that obtained in the electric light, and is certainly comparable with the heat obtained in many processes of manufacture. Indeed, according to some of the most satisfactory investigations which this subject has received, the actual heat at the sun's surface does not very greatly exceed that at which iron melts; while St. Claire Deville even asserts his belief that a degree of heat not greatly beyond that which our physicists have obtained can not possibly be exceeded under any circumstances, either in our own sun or in any of his fellow suns.

Above the glowing photosphere, or light surface of the sun, there extends to a depth of several hundred miles the most wonderful atmospheric envelope known to astrono

mers. In dealing with this envelope, we are touching on the work of the recent eclipse, because, although the envelope had been recognized theoretically two years ago, and its existence demonstrated during the eclipse of December, 1870, yet doubts had continued to be entertained by a few respecting the reality of this relatively shallow atmosphere. We can now, however, speak of it unquestioningly, since scarcely one of those who sought for it during the late eclipse failed to recognize its existence. In the lower part of our own air there is always present, in greater or less quantities, the vapor of water. This vapor rises from wet earth, from rivers, lakes, and seas, and from the wide expanse of ocean, and occupies a certain portion of the lower atmospheric strata. Thus these lower strata form as it were a more complex atmosphere than those above them. Close by the earth there is air and aqueous vapor, while in the higher regions there is air alone; that air being, as we know, composed of a certain admixture of the two gases, oxygen and nitrogen. Now in the case of the sun, a somewhat similar arrangement exists. The lower regions of the solar at mosphere are at all times occupied by certain vapors, which ordinarily do not range to any considerable elevation, simply because they can not remain in the form of vapor except close by the sun. But these vapors are such as we should be rather startled to find in our own atmosphere. We breathe the vapor of water without inconvenience, unless it is present in too great quantities; but if we could imagine for a moment that there were breathing creatures on the sun, these must be able to inhale without injury the vapor of iron, copper, zinc, and others of our familiar metallic elements. For the solar atmosphere, to a depth of a few hundred miles, is loaded with these vapors, all glowing with intensity of heat.

Now Father Secchi announced in 1869 that he had detected traces of just such an atmosphere. For when he examined with his spectroscope the very border of the sun, he found that the dark lines could no longer be seen; as though the light of the glowing vapors themselves,-which exam

ined alone, could show bright lines precisely where the solar dark lines appear,— sufficed exactly to fill up the gaps caused by the absorptive action of those vapors. Secchi reasoned in this way: If we examine the intensely bright light of the sun shining through these vapors, we see that this light is deprived of certain rays, and so dark lines appear; but if we could examine the light of the vapors themselves we should see that this light is composed of these selfsame rays, and so bright lines on a dark background would appear. Now the latter we can not do on account of the extreme shallowness of the complex atmosphere; we can, however, by examin ing the very edge of the sun, obtain light so combining the two kinds, that there will neither be dark lines on a bright background nor bright lines on a dark background, but a continuous rainbow-tinted streak produced by combination of the two.

Du

It seemed to Professor Young, of America, that during eclipses something more might be achieved. For at the very moment when the moon has just concealed the true solar disk, the light of the shallow atmosphere must be shining alone. ring the eclipse of December, 1870, he had his telescope directed (and kept directed by clock-work) toward the point where the moon would obliterate the last fine edge of direct sunlight. And he prepared an ordinary telescope for the use of Mr. Pye, (a young English gentleman residing near the place where Professor Young's party were stationed,) and instructed Mr. Pye what to look for. Both observers found that as the rainbow-tinted streak forming the solar spectrum faded away at the instant of totality, there sprang into view a myriad-lined spectrum-the spectrum, in fact, of the sun's true atmosphere now for the first time recognized.

During the recent eclipse, Colonel Tennant, Captain Maclean, and several other observers, saw the beautiful bright line spectrum of the sun's glowing atmosphere. One or two observers failed to do so; but it need hardly be said that these failures prove nothing except the extreme delicacy of the observation. The positive results, which need alone be considered, prove decisively that next above the sun's light surface there lies an exceedingly complex, but relatively shallow, atmosphere, loaded with the glowing vapors of all those elements

metallic or otherwise-to which the dark lines of the solar spectrum are known to be due.

Next in order comes the sierra, or red envelope, sometimes called the chromosphere, (or more correctly the chromatosphere.*)

The sierra is a far more extensive atmospheric region than the complex atmosphere of Young and Secchi. Its average depth is probably about five thousand miles. Its chief constituent is glowing hydrogen, but it contains other elements, and is indeed far less simple in constitution than was supposed a year or two since. That this is so, is proved by the fact that Professor Young has counted one hundred and twenty lines in the spectrum of this red atmosphere.

Above the red sierra, and reaching even beyond the loftiest prominences, lies yet another atmospheric envelope, the inner corona, as it has been called.

The consideration of this important solar envelope leads us to one of the most important of the discoveries made during the late eclipse. It had long been recognized that the solar corona appears to consist of two portions distinct from each other. The inner portion received (from the Astronomer-Royal, we believe,) the name of the ring-formed corona, because not marked by any noteworthy indentations, gaps, rifts, or the like, but presenting the appearance of a somewhat uniform ring of whitish light around the black disk of the eclipsing moon. It was to this corona that some of the observers of the eclipse of December, 1870, mistakenly supposing its recognition at that time to be a real discovery, proposed to assign the name leucosphere. The term was intended to indicate the apparent whiteness of the inner corona. But under favorable circumstances the envelope presents a slightly ruddy tinge, with traces of green.

Astronomers had begun to recognize the fact that the inner ring-formed corona must be a solar appendage, whatever may be thought of the fainter radiated corona which surrounds it. The light of the ringformed corona had been examined with the spectroscope, and appears to resemble in some respects that of the aurora borealis,

* Strictly speaking, the word chromosphere is as incorrect as phography would be for photography, chromic for chromatic, or (vice versa)

chronatic for chronic.

insomuch that some astronomers expressed their belief that this envelope is a perpetual solar aurora. The startling nature of this conception will be realized when it is mentioned that at a moderate computation the ring-formed corona has a depth exceeding twenty times the diameter of the earth on which we live, while the actual portion of space occupied by these auroral lights (if the theory be true) must exceed the volume of the earth more than fifty thousand times. Besides such displays as these, the most glorious auroras that have ever illuminated terrestrial skies sink into utter nothingness.

But some difficulty was experienced in demonstrating that the spectrum on which these ideas had been based belonged in reality to the ring-formed corona. The study of the sun's surroundings by spectroscopic analysis is not free from certain causes of perplexity. To show how these may arise, we need only consider a case which any one possessing a small spectroscope (one of Browning's miniature spectroscopes, for instance,) can readily test for himself. If such a spectroscope be turned (with suitable precautions) towards the sun, we see the principal solar dark lines, and we know that those lines teach how the sun's light is partially absorbed by the vapors of certain elements existing in his atmosphere. But if next we direct the instrument towards the sky, we see precisely the same spectrum, only reduced in splendor. Yet the vapors of iron, copper, zinc, and so on, do not exist in the sky. The fact really is, that we receive from the sky reflected sunlight, and therefore we can trace in the spectrum of skylight the dark lines belonging to sunlight. And in exactly the same way, the sky during total eclipse, though not very brilliantly illuminated, is nevertheless lit up to some extent by the corona, prominences, and chromatosphere, and therefore the sky-light must supply, however faintly, those bright lines which belong to the spectrum of the gaseous solar surroundings. How is the observer to tell, when he obtains these bright lines from any given part of the corona, that they actually belong to that part of the corona and not to the light of the sky?

Now Professor Young, in December, 1870, dealt with this difficulty in a very subtle and masterly manner. There are two different ways in which spectroscopic analysis can be applied. In one we are

analyzing the light from a considerable range of space, in the other we study only that light which comes from a certain definite direction. Professor Young, who had applied both methods to the shallow complex atmosphere, applied both, with similar success, to the inner corona. Let us suppose that by the former method the whole of the region of sky occupied by the inner corona was supplying light for the spectroscope to analyze; and that by the latter only a fine linear strip from the brighter part of the inner corona was being analyzed. Then clearly and without entering into niceties of detail, if the bright line spectrum we are considering belongs in reality to the inner corona, we should find the true coronal lines relatively much brighter by the former method than by the latter. For in the former there is the great extent of the inner corona to compensate the feebleness of its inherent luminosity, in the latter there is no such compensation.

Carefully studying the relative brightness of the suspected coronal lines, when the two methods of observation were applied, Young inferred that a certain green line belongs unquestionably to a region of luminous matter not less extensive than the inner corona. It appeared tolerably safe to conclude that the inner corona was the actual source of this peculiar light. And if the resemblance between this light and that of the aurora borealis were admitted, it appeared reasonable to infer that the inner corona is a perpetual solar aurora, as had been suggested in 1869.

But although the reasoning of Professor Young was so conclusive that he must be regarded as in effect the discoverer of the important facts just mentioned, yet it seemed desirable to astronomers to endeavor to obtain even more convincing evidence. They had hitherto dealt with the spectral line or lines of the inner corona. Those lines are in reality colored images of the slit through which the spectroscopist admits the light which he proposes to examine; and therefore their shape can teach him nothing about the source of light, their position (or which is the same thing,* their color,) being all that the spectroscopist con

Because a bright line corresponding to any position along the rainbow-tinted spectrum has the color proper to that position. Spectroscopists indicate the position of a line by reference to color -saying a line in the red, or in the blue green, or the like.

siders. But suppose he uses no slit, then instead of a series of images of a slit he will have a series of images of the source of light. If the source of light is the sun or any object shining with all the colors, the different images will overlap and he will see simply "Newton's spectrum," a rainbow-tinted streak of extreme beauty and splendor, but nevertheless what the spectrocopist describes as an "impure spectrum," because in it a multitude of overlapping images are present. If, however, the source of light emits rays of certain colors only, then there will be separate images of these colors, each clearly discernible in all its details. For example, let us suppose that in a little conical flame of great heating power but small luminosity, a chemist places a small quantity of sodium and lithium. Then when he looks at the flame through a spectroscope without using a slit he will see a little conical yellow flame, and close by it a little conical and rather faint orange flame, and farther away a little conical red flame; whereas if he had had a fine slit in his spectroscope he would have seen three fine lines, a yellow one due to the sodium, and two lines, one orange and the other red, due to the lithium.

Now if the reader has followed this brief but necessary explanation, he will see that the astronomer possesses the means of at once solving the difficulty of the corona. So long as he used a slit he obtained a bright green line which might not come from the corona, but from the illuminated sky in the same direction; but if he removed the slit and then saw a green image of the corona, he would no longer be in doubt. For the illumination of the sky could not form an image of the corona, any more than the sky we see in the daytime forms images of the sun, though shining with solar light. If the observer examining the corona with a suitable spectroscope not provided with a slit saw a green image of the corona, it could only be because the green light came from those parts of the sky where the corona was actually seen, and from no other parts.

Now this experiment was precisely what Respighi, the eminent Italian astronomer, determined to attempt. He had an instrument (made for him in 1868) which seemed to him admirably adapted for the purpose; and accordingly he took this instrument with him to India; and stationed

66

at Poodocottah, he successfully applied it to the solution of the problem which had so long perplexed astronomers. His observations involved results of interest, relating to the colored prominences, since these as well as the inner corona were presented in spectrally shifted images. "At the very instant of totality," he says, the field of the telescope exhibited a most astonishing spectacle. The chromatosphere at the edge which was the last to be eclipsed, surmounted by two groups of prominences, one on the right, the other on the left of the point of contact, was reproduced in four spectral colors, with extraordinary intensity of light, and the most surprising contrast of the brightest colors, so that the four spectral images could be directly compared and their minutest differences easily made out. All these images were well defined, and projected in certain colored zones, with the tints of the chromatic images of the corona. My attention was mainly directed to the forms of the prominences, and I was able to determine that the fundamental form, the skeleton or trunk, and the principal branches, were faithfully reproduced or indicated in all the images, their extent being, however, greatest in the red, and diminishing successively in the other colors down to the indigo images, in which the trunk alone was reproduced. In none of the prominences thus compared was I able to distinguish in the yellow image parts or branches not contained in the red image. Meanwhile the colored images of the corona became continually more strongly marked, one in the red corresponding with the red line of

The interest of the question whether such differences would be perceived resides in the fact that the red, green, and indigo images are all due to hydrogen, but the yellow to another element, present in the prominences; and Respighi hoped

to ascertain whether this element extended beyond or not so far as the hydrogen. For our own part we are disposed to place very little reliance on some of the facts observed in this particular part of Respighi's work. With the red and yellow images shining in full splendor he would naturally be unable to see the fainter parts of the indigo images; but these darker images are probably at least as extensive as they are certainly as well defined as the others. For Secchi, in study

ing the prominences by the spectroscopic method, selects the indigo images for the purpose, because he has found that cæteris paribus the indigo images appear the most complete. In Respighi's work other things were not equal. Similar remarks apply to the apparently inferior extension of the blue green image of the inner corona.

hydrogen, another in the green," (corresponding with Professor Young's green line,) "and a third in the blue, probably corresponding with the blue line of hydrogen."

Thus not only has the fact been proved that the light producing the green lines comes, as Young had reasoned, from the inner corona, but also that this corona consists in part of glowing hydrogen. And when we say "in part," we do not mean that throughout a portion of its extent the corona consists of hydrogen; but that one of the elements of which the corona is formed is the familiar gas hydrogen. It appears from the sequent remarks of Professor Respighi that the hydrogen extends as far, or very nearly so, as the matter, whatever it may be, which produces the green light of the corona. Before quoting his words, we remind our readers that what Respighi saw was three pictures of the corona in three different placesone picture produced by the red part of the corona's inherent luminosity, another by the green part, and another by the blue part of that luminosity. The three zones he speaks of are not three distinct envelopes, but three pictures of one and the same element. Just as the spectroscopist in the case of our imaginary experiment with the lamp-flame could not infer that there were three small conical flames, because he saw three images of the single small conical flame, so Respighi knew that the three rings of light which his telescope (spectroscopically armed) presented to his view, were spectral images of one and the same object, the inner ring-formed solar

corona.

"The green zone surrounding the disk of the moon," he says, "was the brightest, the most uniform, and the best defined. The red zone was also very distinct and well defined; while the blue zone was faint and very indistinct. The green zone was well defined at the summit, though less bright than at the base; its form was sensibly circular and it sheight about six or seven minutes," (corresponding to a real depth of from 160,000 to 185,000 miles.) "The red zone exhibited the same form, and approximately the same height as the green; but its light was weaker and less uniform. These zones shone out upon a faintly illuminated ground without any marked trace of color. If the corona contained rays of any other kind, their inten