On September 23, 1699, an eclipse of the Sun occurred which was total to the N. of Caithness for the very brief space of 10-15 secs. At Edinburgh, about 11⁄12ths of the Sun’s diameter was obscured. In the Appendix to Pepys’s Diary[97] there is a letter from Dr. Wallis mentioning that his daughter’s attention was called to it by noticing “the light of the Sun look somewhat dim” at about 9 a.m., whilst she was writing a letter, she knowing nothing of the eclipse.
An eclipse of the Sun occurred on May 12, 1706, which was visible as a partial eclipse in England and was total on the Continent, especially in Switzerland. A certain Captain Stannyan who made observations at Berne, writes thus to Flamsteed[98]:—“That the Sun was totally darkened there for four and a half minutes of time; that a fixed star and a planet appeared very bright; and that his getting out of his eclipse was preceded by a blood-red streak of light from its left limb, which continued not longer than six or seven seconds of time; then part of the Sun’s disc appeared all of a sudden as bright as Venus was ever seen in the night; nay, brighter; and in that very instant gave a light and shadow to things as strong as the Moon uses to do.”
On this communication Flamsteed remarks:—“The Captain is the first man I ever heard of that took notice of a red streak preceding the emersion of the Sun’s body from a total eclipse, and I take notice of it to you [the Royal Society], because it infers that the Moon has an atmosphere; and its short continuance, if only six or seven seconds’ time, tells us that its height was not more than five or six hundredths part of her diameter.”
On the whole, perhaps, the most celebrated eclipse of the Sun ever recorded in England was that of May 3, 1715. The line of totality passed right across England from Cornwall to Norfolk, and the phenomenon was carefully observed and described by the most experienced astronomer of the time, Dr. Edmund Halley. The line of totality passed over London amongst other places, and as the maximum phase took place soon after 9 a.m. on a fine spring morning, the inhabitants of the Metropolis saw a sight which their successors will not see again till many generations have come and gone. Halley has left behind him an exceedingly interesting account of this event, some allusions to which have already been made.
He seems to have seen what we call the Corona, described by him however as a “luminous ring,” “of a pale whiteness, or rather pearl colour, a little tinged with the colours of the Iris, and concentric with the Moon.” He speaks also of a dusky but strong red light which seemed to colour the dark edge of the Moon just before the Sun emerged from totality. Jupiter, Mercury, Venus, and the stars Capella and Aldebaran were seen in London, whilst N. of London, more directly under the central line, as many as twenty stars were seen.
The inhabitants of England who lived in the reign of George I. were singularly fortunate in their chances of seeing total eclipses of the Sun, for only nine years after[99] the one just described, namely, on May 22, 1724, another total eclipse occurred. The central line crossed some of the southern countries, and the phenomenon was well seen and reported on by Dr. Stukeley,[100] who stationed himself on Haraden Hill, near Salisbury. The Doctor says of the darkness that he seemed to “feel it, as it were, drop upon us ... like a great dark mantle,” and that during the totality the spectacle presented to his view “was beyond all that he had ever seen or could picture to his imagination the most solemn.” He could with difficulty discern the faces of his companions which had a ghastly startling appearance. When the totality was ending there appeared a small lucid spot, and from it ran a rim of faint brightness. In about 3½ minutes from this appearance the hill-tops changed from black to blue, the horizon gave out the grey streaks previous to morning dawn, and the birds sprang joyously into the air.
This eclipse seems to have had royal observers. It was watched at Kensington apparently by the King or some of the royal family of England, and at Trianon (Paris) by the King of France,[101] under the competent guidance of Maraldi, Cassini and De Louville. It was the last which was visible as a total one in any part of England.
On May 2, 1733, there was an eclipse of the Sun, which was total in Sweden and partial in England. In Sweden the total obscuration lasted more than 3 minutes. Jupiter, the stars in Ursa Major, Capella, and several other stars were visible to the naked eye, as also was a luminous ring round the Sun. Three or four spots of reddish colour were also perceived near the limb of the Moon, but not in immediate contact with it. These so-called red “spots” were doubtless the Red Flames of the present century, and the luminous ring the Corona.
On March 1, 1737, a good annular eclipse was observed at Edinburgh by Maclaurin.[102] In his account he says:—“A little before the annulus was complete a remarkable point or speck of pale light appeared near the middle of the part of the Moon’s circumference that was not yet come upon the disc of the Sun.... During the appearance of the annulus the direct light of the Sun was still very considerable, but the places that were shaded from his light appeared gloomy. There was a dusk in the atmosphere, especially towards the N. and E. In those chambers which had not their lights westwards the obscurity was considerable. Venus appeared plainly, and continued visible long after the annulus was dissolved, and I am told that other stars were seen by some.” Lord Aberdour mentions a narrow streak of dusky red light on the dark edge of the Moon immediately before the ring was completed, and after it was dissolved. No doubt this is a record of the “Red Flames.”
In 1748 Scotland was again favoured with a central eclipse, but it was only annular. The Earl of Morton[103] and James Short, the optician, who observed the phenomenon at Aberdour Castle, 10 miles N.-W. of Edinburgh, just outside the line of annularity, saw a brown coloured light stretching along the circumference of the Moon from each of the cusps. A “star” (probably the planet Venus) was seen to the E. of the Sun.