In Dr. Curtis's contribution to Rear-Admiral Sand's elaborate report of the eclipse the curious reader will find a very interesting investigation of the aspect of the prominence shown between E and c in fig. 78. He refers all its peculiarities of appearance to the action of a cyclonic storm in the upper regions of the solar atmosphere at this place.

The following account by Mr. G. H. Knight, who studied the prominences with a telescope magnifying

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120 times, is extracted from the Scientific American' of September 11. But fig. 79 is copied from part of a very fine drawing, kindly sent to me by Mr.

Knight. It is the best drawing of prominences as visible during eclipse that I have yet seen. The part of the Sun's edge included in the figure is that lying between G and H in fig. 78. We have only two precious minutes,' writes Mr. Knight in his narrative of the eclipse, and leaving our new acquaintances— Mercury, the sombre woods, the leaden sky, the inky river to other observers, we direct our 120-magnifier to the red specks, some six or seven in number, now plainly discernible around the Moon's margin.

These appearances, when brought within the field of the telescope, show a surprising individuality, and all, by shape, suggest violent disturbance, whose motions are, however, of course invisible by reason of the immense distance, and can be ascertained, if at all, only by a record of impressions of successive observers stationed along the track of the swiftly-gliding shadow. The tube is directed to a point, near the Moon's nadir (uppermost or inverted in the instrument),

* Respecting this drawing Mr. Knight makes the following striking remarks: Of course I am dissatisfied with my effort. Who ever was satisfied in attempting to depict celestial phenomena? Who, for example, ever yet pourtrayed a comet? Still I believe my rude attempt more true to life than any photographs I have seen. One marked peculiarity of such appearances--the delicate blended haze of light-which to some observers extends much further into space than to others, is ignored by the photograph, which is an inveterate Rembrandt in its rejection of middle tints. Then, again, the protuberances and the quivering fringe of fire, of which they are the more salient portions merely, are of various tints of gold, copper, and pink, confessedly difficult colours for actinic action, but which the wonderful camera of the human eye takes in perfectly. Besides which, I had the advantage of a more powerful instrument than any other observer I have heard of.'

occupied by the brightest of these lights (G of fig. 78). The apparition seems to radiate from some point hidden behind the Moon's disc, beyond which it emerges in brilliant silver, copper, and ruby-colored coruscations, the copper tints predominating, and terminates in a circular arc like a half-set Sun. The impression conveyed to an observer is of a vast explosion from a centre some twenty thousand miles below the edge of the Sun's disc, and extending therefrom about fifty thousand miles in every direction.

'About fifty degrees of the Moon's circumference from this prominence we observe a second and wholly different one (F of fig. 78) which bears a grotesque resemblance to a stag's antlers or to the strands of a raveled rope tossed about by a whirlwind. The shape and coruscations of this apparition suggest electrical action (fancy an electric spark 500 miles thick !) or the deflagration of some liquid metal. Its color is crimson; its height about twenty thousand miles.

'Still another and totally different emanation is seen (H of fig. 78). It wears the semblance of a horse's tail, or, more nearly, of a puff of smoke drifting northward, and illuminated by the rosy hucs of sunset.

At this stage of observation some one jogged the instrument, and before it could be adjusted to another group, a glint of sunlight from the disc's right margin blinded our unaccustomed retinas and flooded the landscape with returning day. At the same instant, looking upward, we beheld the Moon's black shadow, sharply defined as a wall in the air, sweep majestically away

from right to left before our very eyes--and the total eclipse of 1869 had become a thing of the past!'*

The spectroscopic study of the coloured prominences, since 1870, has revealed some facts of extreme interest. In the first place, Father Secchi has made a series of observations by which the researches of Zöllner and Respighi are confirmed and supplemented. The following are the chief points in Secchi's latest papers which it seems necessary to notice in this place. I have italicized the facts to which I desire to invite special attention.†

He notes that the chromatosphere presents four aspects, (i) smooth, with a defined outline; (2) smooth, with no definite outline; (3) fringed with filaments; and (4) irregularly fringed with small flames.

He divides the prominences into three orders-heaps, jets, and plumes. The heaped prominences need no special description here; they will be recognized in Zöllner and Respighi's views. The jets are the prominences to which Respighi's description at p. 309 is specially applicable. Secchi notes that their luminosity

*With our present meagre array of facts,' notes Mr. Knight, 'hypotheses are premature. The Sun's heat seems too intense for many of the terrestrial phenomena of chemical action. A cause may, however, exist in meteorolites which, falling with inconceivable velocity and possessing a high spheroidal repulsion, may carry with them into the Sun's seething cauldron a comparatively cold body of disturbing elements and give rise to the mechanical and other perturbations whose manifestations have been noted.

+ Fr. Secchi's paper was received with enthusiasm by the Academy of Sciences, at Paris, and the whole memoir, though exceeding the usual space, was printed in extenso in the Comptes Rendus.

Their

is intense, insomuch that they can be seen through the light clouds into which the sierra breaks up. spectrum indicates the presence of many elements besides hydrogen. When they have reached a certain height they cease to grow, and become transformed into exceedingly bright masses, which eventually separate into fiery clouds. The jet prominences last but a short time, rarely an hour, frequently but a few minutes, and they are only to be seen in the neighbourhood of the spots. Wherever there are jet prominences there also there are faculæ. The plume prominences are distinguished from the jets in not being characterised by any signs of an eruptive origin. They often extend to an enormous height, last larger than the jets, though subject to rapid changes of figure, and, lastly, they are distributed indifferently over the Sun's surface. 'It would seem,' says Secchi, that in jets a part of the photosphere is lifted up, whereas in the case of plumes only the chromatosphere is disturbed.'

On September 7, 1871, Prof. Young, of America, observed the most remarkable outburst from the Sun ever yet witnessed by man. His observation is singularly interesting in itself; but it acquires a fresh interest from the light it throws on observations already described, and more particularly on those made by Respighi and Secchi.

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'On the 7th of September last,' he writes in October, 1871, between half-past twelve and two P.M. there occurred an outburst of solar energy remarkable for its sudden violence.

Just at noon the writer had been