instantly to my eye as I am about to describe, or rather to attempt to give a notion of.

"In the middle of the field was the body of the Moon, rendered visible enough by the light of the corona around, attended by the apparent projections from behind the Moon of which I have attempted to sketch the positions. The effect upon my own mind of the awful grandeur of the spectacle I feel I cannot fully communicate. The prominences were of the most brilliant lake colour,-a splendid pink, quite defined and hard. They appeared to me to be not quiescent; but the Moon passing over them, and therefore exhibiting them in different phase, might convey an idea of motion. They are evidently to my senses belonging to the Sun and not at all to the Moon; for, especially on the western side of the Sun, I observed that the Moon passed over them, revealing successive portions of them as it advanced. In conformity with this observation also, I observed only the summit of one, on the eastern side, though my friends observing in adjoining rooms had seen at least two: the time occupied by my noticing the time and observing with the naked eye not having allowed me to repair again to the telescope until the Moon had covered one, and three-fourths of the other. The point of the Sun's limit where the principal 'flame' appeared was (I judged) a few degrees south of the place where the cluster of spots was situated, and the flame which I observed on the eastern limb was almost exactly where the eastern spot was situated. As, however, some prominences appeared adjacent to parts of the Sun's limit not usually traversed by spots, the attempt to trace a connexion fails. The first burst of light from the emergent Sun was exactly in the place of the chief western flame, which it instantly extinguished.

From the varying lengths of the red flames it is difficult to give an accurate estimation of their magnitude; but the extreme length of the largest, on the western limb, may have been about 2'. This estimation is rather rude, as I was so absorbed in contemplating their general phenomena that I had not time for exact measurement c."

c Mem. R.A.S., vol. xxi. p. 47. 1853.

CHAPTER IV.

OF

THE ANNULAR ECLIPSE OF THE SUN

OF MARCH 14-15, 1858.

Summary of observations in England.

F the different eclipses which have from time to time been visible in England, few have attracted such interest and attention among all classes of society as that of March 14-15, 1858. Though bad weather in most cases interrupted or altogether prevented observations, yet many instructive features were noticed.

Fig. 139.

The line of central and annular eclipse passed across England from Lyme Regis, in Dorsetshire, to the Wash, between Lincolnshire and Norfolk, traversing portions of Somersetshire, Wiltshire, Berkshire, Oxfordshire, and Northamptonshire. The following summary of the observations made, drawn up by Mr. Glaisher, will be read with interest:

"From returns received between Braemar and the Channel Islands, from 30 to 40 in number, it is shewn that the depression of temperature during the eclipse was about 2 at stations north of the line, and nearly 3° at stations on and south of the line of central eclipse; that at places where the usual diurnal increase had taken place in the morning the depression of temperature during the eclipse was greater: and that at places where such increase had not taken place it was less than the

above numbers. Also that at places where the sky was uniformly cloudy during the day the decrease in the readings of a black bulb thermometer was less than 120, while at places where the sky was partially clear the depression was from 17° to 19°, and that, what temperature soever the black bulb thermometer indicated in the morning, it fell during the eclipse to that of the temperature of the air at all places.

"The humidity of the air was such that at places north of the line the wet bulb thermometer read 2·6° less; and on and near the line the depression was 3.2°, and south of it was 37° below the adjacent dry bulb thermometer.

"At some places the humidity of the air increased at the time of the greatest eclipse, but this was far from being universal.

"The sky was partially clear at some places on the east and south coasts, in the Channel Islands and north of Scotland, and it was for the most part overcast elsewhere. Near the southern extremity of the central line the sky was partially clear, and at its northern extremity near Peterborough the clouds were broken; at most intermediate places the sky was wholly overcast. The complete ring was seen at Charmouth, and neighbourhood near Lyme Regis, and at Peterborough, but, so far as I can learn, at no other places. My own station was on the calculated line of central eclipse, near Oundle, in Northamptonshire, and here I saw the Moon and Sun's apparent upper limb coincident, or very nearly so, and therefore that I was situated on or very near the northern limit of annularity, but distant from the centre line by 3 or 4 miles.

"It is very much to be regretted that the unfavourable weather precluded the witnessing the very beautiful attendant phenomena upon large solar eclipses. The time of year was unfavourable to all optical effects-whether of light and shade or colour, independently of the particular character of the day, which was more fatal still to their exhibition, for even where the Sun was visible their presence was only feebly indicated at a few parts of the country.

"At Oundle the weather for some time previous to the commencement of the eclipse was raw and ungenial for the time of year. The wind was gusty and the sky overcast, chiefly with cirro-stratus, and dark scud hurrying past the Sun's place from the north-west, the clouds occasionally giving way and allowing the Sun to be visible by glimpses. Shortly after I o'clock the sky became uniformly overcast, and a small steady rain set in for a considerable time.

"It was long before any sensible diminution of light took place. At 12h 39m a gloom was for the first time perceptible to the north, and the crescent of the Sun shone out with a bright white light between breaks. At oh 43m the gloom was general, excepting around the Sun, which appeared the centre of a circle of light, and illuminated with fine effect some bold irregular masses of cumulus in its vicinity. At oh 45m the gloom increased, slight rain fell, and the wind rose, birds were heard chirping and calling. At oh 53m a severe storm might have been supposed impending, and numerous birds were flying homewards. The deepening of the gloom was gradual but very slow, and between 1 and 1h 1m was at its greatest intensity; but even at this time the obscurity was not sufficient to require that any employment should be suspended. Messrs. Adams and Symons, situated five feet from a shed in an adjoining brickfield, spoke of the gloom as very intense for a period of 10 seconds, and sufficient to render it difficult to take the readings of the thermometer. A body of rooks rose from the ground at this moment and flew homewards; a flock of starlings rose together, and various small birds flew wildly about; a hare was seen

to run across a neighbouring field, as though it were daybreak; straw rustled, and the silence was peculiar and intense. The darkness and lull was that of an approaching thunder-storm. Directly after the greatest intensity the gloom was sensibly and instantaneously diminished, and the day was speedily restored to its ordinary

appearance.

"After oh 50m the lark ceased to rise, and did not sing; at 1h 10m it rose again. The collected information tends to shew that birds and animals, but particularly the former, were affected in some degree in most places; and that it is probable to suppose the gloom was referred by them to the approach of evening, and this not so much from the fact of the gloom as from the manner of its approach, without the accompanying signs of atmospheric disturbance which usher in a storm, and to which birds and animals are keenly sensitive.

"All over the country rooks seem to have returned to their rookeries during the greatest obscuration; starlings were seen in many places taking flight, whole flocks of them together. At Oxford Dr. Collingwood remarked that a thrush commenced its evening song. At Grantham pigeons returned to their cote. At Ventnor Dr. Martin notes the fact that a fish confined in an aquarium, and ordinarily visible at evening only, was in full activity about the time of the greatest gloom. In Greenwich Park the birds were hushed and flew low from bush to bush, and at nearly all places the song of many birds was suspended during the darkness. At Campden Hill it was observed that the crocus closed about the same time, and at Teignmouth that its colour changed to that of the pink hepatica.

"The darkness was not sufficient at any place to prevent moderate-sized print being read at any convenient distance from the eye out of doors, but a difficulty was sometimes experienced in reading the instruments. At Grantham the darkness is described to have been about equal to the usual amount of light an hour before sunrise; near Oxford as about equal to that just after sunset on a cloudy day. The general impression communicated was that of an approaching thunder-storm. The sudden clearing up of the gloom after the greatest phase was likened by more than one observer to the gradual, but somewhat rapid withdrawal of a curtain from the window of a darkened room. The darkness is described to have been generally attended by a sensation of chilliness and moisture in the air. At Oxford the clouds surrounding the Sun were beautifully tinted with red, which merged into purple as the obscuration increased. At Grantham as the eclipse progressed the light became of a decided grey cast, similar to that of early morning, but at the time of the greatest gloom it had a strong yellow tinge. At Teignmouth the diminution of light was very great; the sombre tints of the clouds became much deepened, and the remaining light thrown over the landscape was lurid and unnatural. At Greenwich the appearance of the landscape changed from a dull white to a leaden, and then to a slate-coloured hue; and as the darkness increased it had much the appearance of a November fog closing in on all sides. At Wakefield the tints of the clouds changed from the grey slate colour of clouds in a storm, and became of a purple hue. At Oundle, my own station, the clouds were one uniform leaden grey or slate-colour, and quite in accordance with the general character of the day, nor could I perceive that the clouds appeared lower, or, in fact, that there was any very noticeable departure from the gloom we constantly experience during dull winter weather. Throughout the eclipse it occurred to me that the illuminating power of the Sun was much more than might have been supposed commensurate with the unobscured portion of the disc. When casual breaks permitted it to be visible the illuminated

crescent up to the time of the greatest phase emitted beams of considerable brilliancy, which marked out a luminous track in the gloom, and were clearly and well defined in extent and figure. As the eclipse proceeded a decided change was to be observed in the colour of the Sun itself, which became of a pure silvery brightness, like that of Venus after inferior conjunction with the Sun. The absence of all colour in the light was remarkable, and at the time when the annulus was nearly formed it appeared like a line of silver wire. The departure from the usual amount of light we are accustomed to receive on an ordinarily dull day during the greater part of the eclipse was so inconsiderable, that we might infer approximately the real amount of Sun our average daylight under a cloudy sky is equivalent to.

"As a photometric test during the eclipse, strips of photographic paper were exposed for equal intervals of time every 5 minutes. The result was a scale of tints which exhibited clearly the diminishing intensity of the light up to the period of greatest obscuration, and the rapid increase beyond. The range of tints is low, owing to the cloudy state of the sky, but this does not interfere with the proportionate depths of tint; the time of greatest darkness is distinctly shewn by the very feeble discoloration of the paper. The instruments used at Oundle were made specially for those observations, and were of a very delicate and accurate construction; the meteorological observations were made by Messrs. Adams and Symons.

"In conclusion, I beg sincerely to thank those gentlemen whose returns have supplied the data for this investigation, of which we may say, literally as well as figuratively, that it exhibits only the faint outline of facts dimly visible through a screen of clouds. I think, however, it is reasonable to infer that the great paucity of effects and general phenomena witnessed even in places where the Sun was visible, is due to the conditions of the atmosphere, attributable alike to climate, time of year, and unfavourable weather, and should by no means lessen our confidence in previous accounts of the grandeur and beauty of the attendant phenomenon upon solar eclipses. Optical phenomena, we all know, are dependent upon the medium through which we view them for the nature and power of the effects produced."

Defective as this record is, from a scientific point of view, owing to the unfavourable weather having so generally interfered with observations, yet it has some interest to Englishmen by reason of the fact that phenomena of this character are so rarely visible in England.