gradually receded from the Moon's dark limb, as she moved onwards, and was therefore clearly connected with the Sun. Its form and position with respect to the large prominence continued exactly the same so long as I observed it. On the south limb of the Moon appeared a long range of rose-coloured flames, which seemed to be affected with a tremulous motion. though not to any great extent. The bright rose-red of the tops of these projections gradually faded towards their bases, and along the Moon's limb appeared a bright narrow line of a deep violet tint; not far from the western extremity of this long range of red flames was an isolated prominence, about forty seconds in altitude, and another of similar size and form at an angle of 145° from the north towards the east.'

I may add Mr. Dawes' account of the great prominence marked a in Mr. Airy's picture (fig. 58). A red protuberance of vivid brightness and very deep tint, arose to a height perhaps 14 when first seen, and increased in length to 2′ or more, as the Moon's progress revealed it more completely. In shape it somewhat resembled a Turkish scimitar, the northern edge being convex, and the southern concave. Towards the apex it bent suddenly to the south,-or upwards, as seen in the telescope. Its northern edge was well defined, and of a deeper colour than the rest, especially towards its base. I should call it a rich carmine. The southern edge was less distinctly defined, and decidedly paler. It gave me the impression of a somewhat conical protuberance, partly hidden on its

southern side by some intervening substance of a soft or flocculent character. The apex of this protuberance was paler than the base, and of a purplish tinge, and it certainly had a flickering motion. Its base was, from first to last, sharply bounded by the edge of the Moon. To my great astonishment, this marvellous object continued visible for about five seconds, as nearly as I could judge, after the Sun began to reappear, which took place many degrees to the south of the situation it occupied on the Moon's circumference. It then rapidly faded away, but it did not vanish instantaneously. From its extraordinary size, curious form, deep colour, and vivid brightness, this protuberance absorbed much of my attention; and I am therefore unable to state precisely what changes occurred in the other phenomena towards the end of the total obscuration.'*

Such are a few of the records of the appearance presented by the prominences during the eclipse of 1851. It would have been easy to have filled forty or

* The evidence of Mr. Dawes is very valuable, on account of his exceptional powers of vision.. Probably he has never been surpassed in this respect. It may therefore be regarded as fortunate that he addressed his sole attention to one prominence; since some of the facts he detected are such as no later observations could have more satisfactorily established. Such, for instance, is his observation of the flickering motion of the upper part of the prominence. He was too well accustomed to recognise the apparent motions produced by our own atmosphere to be deceived into inferring real motion where none existed. His observation of the visibility of the prominence for several seconds after the Sun's reappearance confirms Mr. Hind's, and the fact is one of extreme importance, as tending to afford a measure of the luminosity of the larger prominences.

fifty pages with the narratives of the different observers, many of them skilful and well-practised astronomers. All agreed as to the principal details, and, as will be seen by figs. 58-63, there was a very satisfactory agreement in the pictures taken by different observers. It would appear that no doubt could any longer remain that the prominences were solar appendages of some sort. They had been visibly traversed by the Moon, according to the unexceptionable evidence of such astronomers as Airy, Hind, Dawes, and others. They had continued visible when our atmosphere had already begun to be lighted up by the direct rays of the returning Sun. At stations far apart they had presented the same appearance. It would seem therefore that nothing was wanting to establish their real relation to the solar orb, and that no question should any longer have existed as to the fact that the prominences are true solar appendages, since the proofs were so complete that they belonged neither to the Moon nor to our own atmosphere, and, further, that they were not mere optical illusions.

Yet, in the face of all this evidence, some astronomers were still found who maintained that the observations were insufficient to establish the existence of coloured objects so enormous as these must be if they really were solar appendages. It has always happened that in the ranks of the scientific army some have been found who refuse to credit the marvels which observation is continually revealing on every hand. Despite all the known wonders of the universe, the mere

circumstance that the sole available interpretation of observed facts involves some surprising conclusion, is held by such men to be a sufficient reason for rejecting the observations of the most trustworthy astronomers.* So it was in this instance. For nine long years astronomy was compelled to wait before she could be allowed to take possession of her well-won new territory. The amazing fact had been proved beyond all possibility of reasonable question that the great globe of

* One is almost ready to despair of the cause of scientific progressto despair at least that that progress will ever be so rapid as it might readily become—when one finds that each new result must be established over and over again before it is admitted by a large proportion of the scientific world. It may be remarked, indeed, that the progress of science has been at least as seriously checked by undue caution as by undue boldness. It would seem almost as though some students of science were continually in dread lest the work of our observers should become too productive. The value of scientific observation seems to be enhanced in their eyes precisely in proportion as its fruits are insignificant. In all ages there have been those who would thus unwisely restrain the progress of legitimate inquiry. We must not admit that Jupiter has moons,' they said of old; the Evil One may have sent these appearances to deceive us. Let us wait for further observation.' 'The Sun cannot have spots,' they reasoned again, for the Eye of the Universe cannot suffer from ophthalmia. These things are illusions; let us wait for more satisfactory observations.' 'The idea that the Sun-spots wax and wane in a definite period is too fanciful for acceptance; and still more absurd is the conception that terrestrial magnetism can have any relations whatever with the progress of solar disturbance. We must wait for fresh researches.' 'Who can believe that flames, or clouds, or mountains, many times exceeding the Earth in magnitude, exist upon or close by the Sun? These things must needs be illusions; at any rate, fresh observations are required before such marvels can be admitted.' And as this has happened with facts now accepted, so it is happening, and so (it is feared) it will always happen, as respects many other facts which have been in truth demonstrated, but the demonstration of which does not chance to lie exactly on the surface.

the Sun is surrounded by a deep layer of coloured matter, while from portions of this vast envelope enormous protuberances start out, their height so vast that ten globes such as our Earth might be piled one upon the other on the Sun's surface without attaining to the summit of the highest prominences. But this great fact was not to take its place in our treatises of astronomy until, although twice proved already, it had been proved once again at least.

Accordingly, in 1860, when a total eclipse was to be visible in Spain, preparations were made for finally resolving the problem of the prominences. A host of skilful observers devoted their powers to demonstrating what had already been abundantly demonstrated. It happened fortunately, however, that amongst the astronomers who took part in observing this important eclipse, there were some few who duly recognised the importance of the occasion, and who therefore, leaving fruitless labours to others, applied themselves to solving important questions respecting the coloured prominences. Their results I now propose to describe; but, in the first place, I will quote the account which Goldschmidt, one of the most skilful telescopists of modern times, gave of the prominences visible on this occasion. Some of the facts recorded by him are of extreme interest and importance, especially as respects the colour of the prominences, since M. Goldschmidt's practice as a painter gave him exceptional experience in this respect.

M. Goldschmidt employed a telescope of four inches