the eclipse of August 1869), that the corona is of the nature of a solar

aurora.

But if we consider the evidence, we find that it does not throw any satisfactory light on the chief question at issue the question, namely,

of the corona's extension.

Illuminated as our own air must needs have been by that intensely bright part of the corona which lies close to the sun, the coronal spectrum might well be given by the light from our atmosphere. There was, indeed, a way of determining whether this was so or not. Of course, the portion of the atmosphere lying directly towards the moon would be illuminated by the corona as fully as the portion outside; unless indeed there were haze in the air, in which case the figure of the coronal ring would be in some sort represented, though with considerable expansion, in the resulting halo. If, then, the spectroscope were directed to the moon's seemingly dark disc, the bright lines of the corona ought to be visible about as clearly as when the spectroscope was directed outside the true limits (whatever they may be) of the corona. Captain Maclear found that the bright lines of the corona were visible in the light received from the direction in which the moon's centre lay; but the lines were not half so bright as those seen when the spectroscope was directed to a distance from the moon's edge (outside of it) equal to about one-fourth of the moon's apparent diameter. This would imply that in the latter case the spectroscope was still directed to a spot within the real limits of the corona, or rather of that portion of the corona which is partly gaseous.

It will be seen, however, that considerable doubt rests on the spectroscopic observations, so far as they bear on the question of the real extension of the corona. In this respect, indeed, they can scarcely

give either negative or positive evidence which can be trusted. For even if the bright line spectrum were not given by light beyond a certain distance from the sun, it would by no means follow that the coronal light in that direction did not come from a real solar appendage. The gaseity of the corona might be limited to certain distances from the sun, although the corona itself extended very much farther. Nor, again, can the positive evidence supplied by the visibility of the bright lines at considerable distances from the sun be trusted implicitly, since, as we have seen, our atmosphere may reflect the light which supplies those bright

lines.

Thus the whole question of the corona's extension depended on the success of those who sought for evidence of the fixity of coronal radiations seen at any given station, and of the identity of radiations so seen from different stations.

So far as ordinary methods of observation were concerned, there was little reason for hoping that this particular eclipse would give better results than former ones. If any eclipse could have settled the question, one would have supposed the American eclipse of 1869 would have done so. For then the corona was seen from a number of stations along a track crossing the whole breadth of North America; favourable weather was nearly everywhere experienced; skilful observers were prepared to note the appearance of the coronal radiations; and finally, it was hoped that photographers might succeed in obtaining good pictures of the corona. But inasmuch as the photographs actually obtained only showed the brightest part of the corona, all depended on direct observation; and in this, as in many former instances, discrepancies appeared in the various accounts, while the sketches differed also con

siderably inter se. Observers agreed in describing the corona as fourcornered in figure; but as to its colour, its extension, and the exact position of the radiations, they were not by any means in satisfactory agreement. The question remained in abeyance and many were disposed to believe that the recent eclipse would leave this particular problem still unsolved.

Now as respects direct observations last December, though there was much that seemed to indicate that certain radiations were seen from different stations, and that these radiations remained unchanged in position during totality, there was still an element of uncertainty. Mr. Langley, in the account from which I have already quoted, fairly sums up the results of observation: 'In some well-marked features all agree, in other minor ones such differences exist that one might almost say each saw a different corona.' Mr. Lockyer, indeed, was so far misled by the apparent discordance between the accounts which reached him, as to pronounce with some degree of definiteness the opinion that the coronal radiations were demonstratively terrestrial phenomena, speaking of the evidence afforded by this discordance as supplying the strongest proof of the variability of the outer corona.'

But at this time the photographs taken in Spain and Sicily had not been compared with each other, or with the drawings of different observers. Nor, indeed, was Mr. Lockyer, who wrote his account from Venice (and had not been favoured with a view of the eclipse), aware of one strongly marked feature in the drawings taken in Spain, which promised to give decisive

evidence on the point at issue. At three stations, forming a triangle with sides five or six miles long, near Cadiz, a well-marked V-shaped gap with clearly defined bounding radiations, opposite the moon's south-eastern quadrant, had been noticed as the most prominent feature of the corona. It had remained unchanged in position during the whole continuance of totality, although the play of light and shade over the eclipsed sun had been considerable. It was pictured in a large drawing exhibited by Lieut. Brown at the January meeting of the Royal Astronomical Society. At the same meeting Mr. Hudson, a fellow of St. John's College, who had seen it from another station, remarked that in the picture, marked as this feature was, it was not so marked as it had appeared to himself; and Lieut. Brown admitted that his picture did not present this striking feature to his own satisfaction.

If only all the evidence here stated could be admitted as certain, the question of the existence of real solar radiations to a distance nearly equal to the moon's apparent diameter was demonstrated. But doubts were still expressed whether the accounts. and drawings disposed finally of the question.

At the same meeting photographs. by Lord Lindsay were handed round, and these seemed scarcely to confirm the view that this great Vshaped gap really existed in some vast solar appendage. In these photographs no very considerable extension of the corona could be traced, and it seemed open to question whether, in taking so many as nine, Lord Lindsay had not unduly shortened the exposure for each.1

Again, there were obvious signs in the best of the photographs exhibited that at Lord Lindsay's station a haze or some other atmospheric cause had tended to mar the distinctness of the corona; for the disc of the moon, especially on the side where the corona was brightest, was illuminated with a light far too strong to be otherwise explained (assuming always that all the photographic operations had been satisfactorily performed).

But after this meeting attention was directed to a photograph taken by the American observers at a station close by. In this photograph only a portion of the corona was shown; but the extension of the corona was considerably greater than in any photographs which had hitherto been taken; and there, in the south-eastern quadrant, was that very V-shaped gap of which the observers had spoken, and which Lieut. Brown and others had depicted. It was not a mere faintly seen or perhaps half-suspected feature, but the most striking feature in the photograph.

One thing only was required to remove all shadow of doubt. News had reached England that Mr. Brothers had been most successful in photographing the corona at his station near Syracuse. In the fifth plate of six he had taken 'the corona is shown,' said the account, as it was never seen on glass before.'

6

Here a crucial test seemed available. If the great gap opposite the south-eastern quadrant was not seen in this photograph, negative evidence, about as strong as negative evidence could be in this case, would be supplied against the theory that the radiations are true solar appendages. On the other hand, if the great gap appeared in the photograph, then positive evidence of the

most convincing kind would be afforded on this interesting ques tion.

I was so fortunate as to be the first to receive intelligence on this point. Mr. Brothers forwarded, through me, to Dr. Huggins, a rough drawing of his best photograph, and in that picture the Vshaped gap appears as the most striking feature of the corona. It is more plainly shown than in the American photograph, and its borders can be traced very much farther from the sun. The photograph, indeed, fairly bears out the statement that the corona is shown as it was never seen on glass before; it is facile princeps among photographs of the corona: but, except in this greater clearness and extension, the figure of the great gap and of the bounding radiations agrees perfectly with the American photograph.

At length, then, we have evidence which cannot be questioned on this long mooted point. The corona itself has left us an unmistakable record, has written down in the plainest possible characters a statement of its true nature. By a piece of good fortune such as few were so sanguine as to anticipate, a feature strongly marked enough to be recognisable beyond the possi bility of question has been depicted in two exceptionally successful photographs, taken at widely separated stations. This one feature proves all that we require. Granted that two radiations (for the gap implies necessarily the existence of two bounding rays) exist in some real solar appendage, it will no longer be doubted that radiations of the same nature exist all round the sun. Nor will it now be questioned that the faint prolongations of such radial beams, seen when eclipses are viewed under very favourable circumstances,

at Bordeaux of CHUNG

HOW, an Envoy of the Chinese Government, despatched on a propitiatory mission to France after the massacre of nearly all the French subjects, including the Consul, at Tientsin. The appearance of this high officer in Europe marks an epoch in the history of China. It is the first time that a Chinese of unquestionable rank and high official position has been accredited to any European Power. He is not only one of the high officers of the Empire, and related to the Imperial family, but he is one of their Statesmen. Hitherto it has been thought sufficient, as in the case of the Burlingame mission, to select from the Foreign Office in Peking subordinates clerks or humble secretaries in the Department-and give them a provisional and altogether temporary rank as Minister, on the clear understanding that their commission ran only during residence in foreign countries. Very much as local military rank is conferred with us when officers are sent to foreign countries on special service.

Chung-how has, on the contrary, long held high and responsible office as Imperial Commissioner and Superintendent for the five Northern Ports. He has also been entrusted with the creation of a great arsenal at Tientsin for the manufacture of powder, the casting of cannon, &c. In this many foreign engineers, chiefly British, have been employed; while the whole plant of the machinery has been imported from England. In the capacity of Director of this great establishment he has shown intelligence and energy; as well as a willingness to accept responsibility, and incur large expenditure for public purposes, very unusual in Chinese mandarins. In this posi

contact during several years with foreigners of all classes and nations -with officials, merchants, travellers, and his own artisans, many of a superior class-and to all he was so favourably known that it was fondly hoped he was gradually being educated to appreciate the superiority of European culture and science. Of the advantages China might derive from freer intercourse, and the enlightened application of European skill and science in developing the resources of his country, he could hardly fail to be convinced. He has shown anxiety to possess at any cost the best machinery Europe could supply for his arsenal, and a line of rail, some two miles in length, completely encircled and connected all the scattered workshops and buildings, and last year locomotives had been ordered to utilise it. To him belongs the credit therefore of having been the first to make a railroad in China, and on his own responsibility. The extension of this line, or a tramroad, to the mouths of the coalpits some miles distant on which he depended for his fuel, was in contemplation, and seemed, under his energetic impulse, to be only an affair of time, despite all the opposition which every proposition of this kind emanating from the Foreign Legations had encountered from the Government in Peking. Seeing what he had so far accomplished, and the favour he was held to enjoy with the two Empresses, there seemed to be good ground for sanguine hopes. His powerful physique, in its promise of activity as well as energy, seemed to lend a sanction to the hopes entertained. He is a large-framed, burly-looking Tartar-a sort of Eastern type of