vision a kind of ghostly radiance, composed of separate pearly beams, looking distinct each from each, as though the black circle where the Sun once was, bristled with pale streamers, stretching far away from it in a sort of crown. This was the mysterious corona, only seen during the brief moments while the shadow is flying overhead."

The French astronomer, Flammarion, says in his "Popular Astronomy," "What, then, is the corona? It is probably a region in which is found a variable quantity of detached particles, partially or wholly vaporized by the intense heat to which they are exposed. But how can these particles be supported in these burning heights? To this question we are already able to give three replies: (1). The matter of the corona may be in a state of permanent projection, being composed of substances incessantly darted out by the Sun and falling back on him. (2), The coronal substance may be more or less supported in the solar heights by the effect of a calorific or electrical repulsion. (3), Finally the corona may be due to clouds of meteors, aerolites circulating around the Sun in his immediate vicinity. All these explanations are perhaps in part true." In Proctor and Ranyard's "Old and New Astronomy " we read as follows: "But it is evident on the one hand that no simple theory can be advanced in explanation of the phenomena of solar appendages manifestly complex and varied, and on the other that the details of coronal structure and of coronal phenomena present problems far too difficult to be as yet solvable."

Miss Clerke in her "History of Astronomy during the Nineteenth Century," says "The corona is properly described as a solar appendage, and may be conjecturally defined as matter in a perpetual state of efflux from, and influx to our great luminary, under the stress of electrical repulsion in one direction and of gravity in the other. Its constitution is of a composite character. It is partly made up of self-luminous gases, chiefly hydrogen, and the unknown substance giving the green ray, “1474;” partly of white-hot solid or liquid particles, shining with continuous light, both reflected and original. The coronal materials must be of inconceivable tenuity, since comets cut their way through them without experiencing sensible retardation. Summing up what we have learned about the corona during some forty-five minutes of scrutiny in as many years, we may state, to begin with, that it is not a solar atmosphere. It does not gravitate upon the Sun's surface and share his rotation, as our air gravitates upon and shares the rotation of the earth; and this

for the simple reason that there is no visible growth of pressure downward in its gaseous constituents; whereas, under the sole influence of the Sun's attractive power, their density should be multiplied many million times in the descent through a mere fraction of their actual depth."

It is easily seen from the preceding extracts that the corona of the Sun has been visible only on those rare occasions when solar eclipses are total; and the very short period of time during which a total eclipse lasts at any given point upon the Earth's surface, renders any examination of the corona a very difficult operation. Since the introduction of the camera and the spectroscope, as adjuncts in all solar research, the amount of time and labor devoted to such work has been multiplied more than twofold. All the great observatories of the world are systematically engaged in trying to solve the mystery of the corona. Mountain peaks, clear skies, and rare atmospheres, have been sought for, and expensive trips to far away lands have been undertaken, in order to determine once for all what this wonderful thing may be which persists in withholding from the inquisitive eye its secrets and its nature. Men have gone half way round the globe to witness for one, two or six or seven minutes at most, the most beautiful object visible in the solar system. The question naturally arises-is it possible, or will it ever be possible, for the human eye, with or without any kind of instrument, and at any time to look upon and examine at leisure, such a glorious appendage as that of the Sun's corona? Will this nineteenth century, so full of splendid achievement in every field of scientific research, add to its other honors that of having made it possible, in the absence of a total eclipse, to see the corona? All efforts hitherto made have been without avail, have utterly failed.

In 1866, Mr. Lockyer, and in 1868, Janssen, made it possible for one to see at any time of the day when the Sun is above the horizon, and not obscured by clouds, the so-called "protuberances" or "prominences," that up to that time had been considered as mysterious as the corona is now. Miss Clerke says"The eclipse of 1868 is chiefly memorable for having taught astronomers to do without eclipses, so far, at least, as one particu lar branch of solar inquiry is concerned. Inspired by the beauty and brilliancy of the variously tinted prominence-lines revealed to him by his spectroscope, Janssen exclaimed to those about him, "Je verrai ces lignes-là en dehors des eclipses!" On the following morning he carried into execution the plan which formed itself in his brain, at the time of the eclipse.

More than a year ago an idea took possession of my brain that there must be some method by which the corona of the Sun may be rendered visible at any time between sunrise and sunset, atmospheric conditions being favorable. In the latter part of April, 1899, I secured three strips of pine lumber, each about six or seven feet long, and of a uniform thickness of threefourths of an inch. The strips were fastened to the outside of the tube of a Clark telescope of six inches object glass, separated from each other by a distance of 120°. Ordinary wrapping twine was used with which to make the strips secure and firm in their position. They were so placed that about three feet of each one was allowed to project beyond and in front of the object glass. This done, a card board, sufficiently heavy, was cut into the form of a circular disc of seven inches diameter. Upon the inside of the circumference of the disc, and as close to the limb as possible three small holes were pierced, through which pieces of fine, flexible wire were put, and these were tied around the pine strips. By this arrangement the card-board disc-an artificial moon-could be securely heid in position, and by slipping the wires forward or backward, as might be necessary, the disc could be made to hide completely the entire face of the Sun. It was expected and hoped that the effect would be the same as in the case of a true solar eclipse, that is, that the solar appendages would be revealed. All things being ready, the telescope mounted firmly upon the tripod, the pine strips fastened, and the card-board moon put at a suitable distance from the object glass, on the afternoon of May 3d, 1899, the first trial was made, an observation was taken. The face of the Sun being completely obscured, bright radiations were seen to issue from the limb of the artificial moon in great numbers. These radiations were carefully scrutinized, but it was soon made apparent that they were nothing but streaks of light of a decidedly brassy appearance, reflected from the inside of the telescope, the barrel of which was made of brass. The card-board moon was now shifted to a point a little farther away from the object glass. The result was still the same, the brassy streaks, and all else. During all this time, and in spite of every effort to prevent it, the barrel of the telescope was flooded with light that poured into it from the surrounding atmosphere. Just here seemed to be the difficulty, the light came into the telescope apparently from every where past the limb of the false moon.

For over an hour, slight changes were made in the position of the false moon, at intervals of from five to six minutes each, at

one time to a place nearer the object glass, at another to a point further away, but all to no effect, the results were invariably the same, save that the brassy streamers were modified accordingly. Matters were becoming monotonous and rather disheartening, so much so that the question arose whether the observation should be prolonged, or given up as a flat failure. The determination to succeed, or know the reason why success should not be attained, prolonged the work for some time longer. The time passed in shifting the false moon, readjusting the pine strips, keeping the telescope in proper position, straining the eye in order to see the sight should a revelation be made, yet nothing was seen but the brassy reflections from the telescope itself, which seemed to be dancing and laughing as if in very mockery at every attempt to succeed. More than two hours had passed, and the goal to be reached was apparently as far off as ever. The observer was quite disheartened and discouraged, and about ready to give up in despair. In such a frame of mind, and quite willing to give it up as a bad job, suddenly and unexpectedly the false moon, for some reason or other, changed its position. slightly, so that apparently its surface and the surface of the object glass were no longer parallel to each other. Whether the lack of parallelism was a fact or not, cannot now be determined. The effect produced was that the barrel of the telescope seemed to be completely filled with absolute darkness, the brassy streamers vanished, and along the upper right hand limb of the false moon appeared in all their beauty and soft light the coronal

There was no mistaking the vision. It was the genuine corona itself, "a thing of beauty," and a glorious recompense for the time and labor that had been expended.

An attempt to change the position of the telescope so as to hold the Sun in the field, resulted in destroying the vision, and the coronal streamers disappeared from view. The following is a fac simile of a hand made drawing of the corona as seen on the afternoon of May 3d, 1899. It is not a complete coronal form, for the reason that the cardboard disc extended beyond the limb of the Sun, and prevented a view of the streamers other than as represented.

Several cardboard discs, one six inches in diameter, one seven, and another eight inches in diameter, were made and used at varying distances. A great many obstacles had to be met and surmounted in preparing for the work, and great care had to be exercised in handling the apparatus. The telescope used was mounted on a tripod, and was exposed to the action of the wind.

There was no driving clock attachment, so that every movement had to be made by the observer, thus rendering the labor so much the more difficult. Other observations were taken in May

OBSERVATION OF SUPPOSED CORONA OF THE SUN WITHOUT AN ECLIPSE.

and in June, but on account of ill health, the observations had to be suspended during the summer, and there has been no opportunity since to resume them.

But that the corona of the Sun was seen on the 3d of May, 1899, a day upon which there was no eclipse of the Sun, either partial or total, can scarcely admit of doubt. There is a possibility that it may have been a vision of something else, an optical illusion, an "ignis fatuus," or a dream.

At the moment when the picture was sketched, the "apparition" was situated in the vicinity of one of the poles of the Sun, and not in the plane of the Sun's equator, and so clear and well defined was the shape, and so different from all other appearances, that the conclusion reached by the observer was that it was the corona itself. To be sure, he may have been mistaken, but he thinks not, and it is unfortunate that the observation of