CHAPTER XVII.

CATALOGUES OF ECLIPSES: AND THEIR CALCULATION.

This must of necessity be a brief chapter, so far as mere lines of text are concerned, but it will not on that account be unimportant. It will be evident to the reader that many more eclipses of interest have happened, and will happen, than it has been possible to speak of in these pages. Accordingly, as it is one of the main objects of this series of volumes to create a thirst for knowledge, to be satisfied by the study of other and bigger volumes, it will be desirable to furnish a list of some of the various books and publications, in which eclipses will be found catalogued or described in detail, so that readers desirous of pursuing the matter further, may possess facilities for doing so.

By far the most complete and comprehensive catalogue of solar eclipses is that prepared some years ago by an Austrian astronomer, the late Theodore Von Oppolzer of Vienna, and published under the title of Canon der Finsternisse, in the Memoirs of the Imperial Academy of Sciences.[144] This work supplies approximate calculations of about 8000 eclipses of the Sun, for a period of more than 3000 years, from November 10, 1207 B.C. (Julian Calendar), to November 17, 2161 A.D. (Gregorian Calendar). There are appended 160 charts, of all the principal eclipses; but as the charts only exhibit the beginnings, middles, and ends of the eclipses dealt with, they are frequently misleading, because the intermediate lines of path are, in many cases, more or less considerably curved.

Another very important and comprehensive catalogue of eclipses, solar and lunar together, will be found in the well-known French work, L’Art de vérifier les Dates,[145] compiled by a member of the religious order of St. Maur. One volume of this famous work contains eclipses from the year 1001 B.C. to the Christian Era, whilst another volume gives a similar catalogue from the year 1 A.D. to 2000 A.D. The other volumes deal with chronological matters only. Although not strictly a work of extreme astronomical exactness, yet L’Art de vérifier les Dates stands unrivalled as a record not only to subserve the purpose indicated by its title, but of the bare facts of the eclipses which have happened during the period of 3000 years stated above.

There has not been much done in England in the way of publishing eclipse records or tables, past or future, but in the British Almanac and Companion for 1832 there is given a catalogue, which was useful in its day, of eclipses, then future from 1832 to 1900, omitting, however, solar eclipses hardly visible to any inhabited portion of the Earth, and lunar eclipses where the part of the Moon’s diameter obscured was less than 1⁄12th.

In by-gone days several attempts were made to gather together in a tabular or paragraph form the details of eclipses which had happened, and some of these have been important sources of information for the guidance of us moderns. Foremost amongst these efforts must be named the Almagestum Novum of J. B. Ricciolus.[146] This work contains a catalogue of eclipses observed from 772 B.C. to A.D. 1647, and continued in tables to A.D. 1700. It is prefaced (pp. 286-8) by a long series of quotations from classical authors relating to eclipses, some few of which have already been mentioned in these pages.

Kepler paid much attention to eclipses, and left behind him a large mass of notes and original observations. These will be found chiefly in his Astronomiæ Pars Optica, c. vii. § 2, originally published at Frankfurt in 1604. The most convenient and accessible edition of this is to be found in Frisch’s reprint of all Kepler’s works.[147]

Tycho Brahe also gathered together from various sources many observations of eclipses, and combined them with a number of his own, the whole being published in his Historia Cœlestis.[148] Tycho Brahe was a very interesting personage in spite of the fact that he went all astray on the subject of the system of the Universe, and he well deserves, what has been given to him, a book[149] all to himself. It is peculiarly appropriate that I should give him a good word in this little volume on eclipses, because it was the solar eclipse of Aug. 21, 1560, which first seriously led him to take up astronomical pursuits, he being then 14 years of age, and struck with wonder that eclipses could be predicted.

A vast amount of historical and other information respecting eclipses will be found in a book, the latinised name of whose author is Sethus Calvisius. The title of the work is Opus Chronologicum.[150] The historical matter is very much mixed, but the eclipses can be got hold of through the Index, which is very full. P. Gassendi,[151] a well-known astronomer of the 17th century, left behind him observations of many eclipses observed by himself between 1628 and 1655. In a book entitled An Introduction to Universal Geography,[152] one Nicolas Struyck in the middle of the 18th century published a very full array of eclipse observations collected with infinite pains from an endless variety of authors ancient and modern.

In 1757 the well-known James Ferguson reprinted in his Astronomy,[153] but in a very condensed form, all Struyck’s eclipses from 721 B.C. to A.D. 1485. Then he carried on his catalogue to 1800 by means of the materials furnished by Ricciolus and L’Art de vérifier les Dates. Ferguson also invented a machine for illustrating mechanically the circumstances of an eclipse. He called it the “Eclipsareon.” A full description is given in his book, mentioned above, but I do not know whether any such instrument is still in existence, or, if so, where it is to be found.

Ferguson apologises[154] for the incompleteness of his eclipse information in the following words:—“I have not cited one half of Ricciolus’s list of portentous eclipses, and for the same reason that he declines giving any more of them than what that list contains, namely, that ‘tis most disagreeable to dwell any longer on such nonsense, and as much as possible to avoid tiring the reader. The superstition of the ancients may be seen by the few here copied. My author further says that there were treatises written to show against what regions the malevolent effects of any particular eclipse was aimed, and the writers affirmed that the effects of an eclipse of the Sun continued as many years as the eclipse lasted hours, and that of the Moon as many months.”

The most comprehensive (indeed almost the only) modern English book on eclipses is the Rev. S. J. Johnson’s,[155] of which frequent use has already been made in these pages. It contains a vast amount of matter put together in a condensed form but the references to authorities are rather defective and deficient. Less comprehensive in one sense yet exceedingly valuable and interesting as a succinct summary of solar eclipse knowledge up to the date of 1896 is Mrs. D. P. Todd’s excellent little volume[156] which has been several times quoted on previous pages. On various occasions in 1890 and following years Professor J. N. Stockwell contributed to the American Astronomical Journal a number of papers[157] discussing in a very interesting and exhaustive manner many of the eclipses recorded by the ancient classical authors. These papers should be consulted by all who desire to realise the value of eclipse records in connection with mundane chronology.

The calculation of eclipses is a matter of some interest. It is beyond the scope of the present work to explain even in outline the methods in use, but with the aid of the books mentioned below[158] a reader possessed of the necessary time, mathematical knowledge, and patience, will be able to pursue this matter as far as his inclination may lead him. Johnson has found very useful the tables given in the eighth edition of the Encyclopædia Britannica (Article, “Astronomy”) but strange to say these tables do not appear in ninth edition of that famous work.

Lalande[159] has given numerous references to eclipses of the Sun during the 16th, 17th and 18th centuries which may be useful to those who wish to work at the history of eclipses.

CHAPTER XVIII.

STRANGE ECLIPSE CUSTOMS.

I had intended heading this chapter “Eclipse Customs amongst Barbarous Nations,” but in these days it is dangerous to talk of barbarians or to speak one’s mind on points of social etiquette so I have thought it well to tone down the original title, otherwise I should have the partisans of the “Heathen Chinee” holding me up to scorn as a reviler of the brethren.

Did space permit a very interesting record might be furnished of eclipse customs in foreign parts.

An eclipse happened during Lord Macartney’s embassy to China[160] which kept the Emperor and his Mandarins for a whole day devoutly praying the gods that the Moon might not be eaten up by the great dragon which was hovering about her. The next day a pantomime was performed, exhibiting the battle of the dragon and the Moon, and in which two or three hundred priests, bearing lanterns at the end of long sticks, dancing and capering about, sometimes over the plain, and then over chairs and tables, bore no mean part.

Professor Russell, who is quoted elsewhere in this work with respect to Chinese eclipses, makes the following remarks in regard to what happens now in China when eclipses occur:—“It will be interesting here to note that, even at present, by Imperial command, special rites are performed during solar and lunar eclipses. A president from each of the six boards, with two inferior officials, dressed in their official clothes, proceed to the T’ai-Ch’ang-Ssu. When the eclipse begins they change their robes for common garments made of plain black material, and kneeling down, burn incense. The president then beats one stroke on a gong, and the ceremony is taken up by all the attendant officials.”

A writer in Chambers’s Journal[161] in an article entitled “The Hindu view of the late Eclipse,” gives an interesting and original account of divers Hindu superstitions and ceremonies which came under his notice in connection with the total eclipse of the Sun of Aug. 18, 1868. He remarks that “European science has as yet produced but little effect upon the minds of the superstitious masses of India. Of the many millions who witnessed the eclipse of the 18th of August last there were comparatively few who did not verily believe that it was caused by the dragon Rahu in his endeavour to swallow up the Lord of Day.... The pious Hindu, before the eclipse comes on, takes a torch, and begins to search his house and carefully removes all cooked food, and all water for drinking purposes. Such food and water, by the eclipse, incur Grahana seshah, that is, uncleanness, and are rendered unfit for use. Some, with less scruples of conscience, declare that the food may be preserved by placing on it dharba or Kusa grass,” and much more to the like effect is duly set out in the interesting article cited.

During the total eclipse of the Sun of Aug. 7, 1869, the following incident is noted[162] to have occurred at a station on the Chilkaht river, in Alaska, North America, frequented by Indians:—

“About the time the Sun was half obscured the chief Koh-Klux and all the Indians had disappeared from around the observing tent; they left off fishing on the river banks; all employments were discontinued; and every soul disappeared; nor was a sound heard throughout the village of 53 houses. The natives had been warned of what would take place, but doubted the prediction. When it did occur they looked upon me as the cause of the Sun’s being ‘very sick and going to bed.’ They were thoroughly alarmed, and overwhelmed with an undefinable dread.”

A still more thrilling incident is thus recorded[163] of the eclipse of July 29, 1878, by a witness at Fort Sill, Indian Territory, U.S.:—

“On Monday last we were permitted to see the eclipse of the Sun in a beautiful bright sky. Not a cloud was visible. We had made ample preparation, laying in a stock of smoked glass several days in advance. It was the grandest sight I ever beheld, but it frightened the Indians badly. Some of them threw themselves upon their knees and invoked the Divine blessing; others flung themselves flat on the ground, face downward; others cried and yelled in frantic excitement and terror. Finally one old fellow stepped from the door of his lodge, pistol in hand, and fixing his eyes on the darkened Sun, mumbled a few unintelligible words and raising his arm took direct aim at the luminary, fired off his pistol, and after throwing his arms about his head in a series of extraordinary gesticulations retreated to his own quarters. As it happened, that very instant was the conclusion of totality. The Indians beheld the glorious orb of day once more peep forth, and it was unanimously voted that the timely discharge of that pistol was the only thing that drove away the shadow and saved them from the public inconvenience that would have certainly resulted from the entire extinction of the Sun.”

A certain Mr. F. Kerigan, in a book published in 1844, made the following remarks on ancient Jewish ideas respecting eclipses:—

“The Israelites, like their benighted neighbours, esteemed an eclipse of either luminary as a supernatural and inauspicious omen, which filled them with the most gloomy and fearful apprehensions: as may fairly be deduced from the 8th chapter of Ezekiel, v. 15: ‘Then he brought me to the door of the Lord’s House, which was towards the N.; and, behold there sat women weeping for Tammuz.’ Now Tammuz is the name under which Adonis was known in Palestine: he was the favourite of Venus, or Astarte, the principal goddess of the Philistines and Phœnicians. Being killed by a wild boar, the prevailing superstition of the age induced the uninformed multitude to believe that when the Moon was eclipsed, it was in complement to their beloved goddess Venus or Astarte, who, concealed behind the full Moon, sat weeping under a dark veil for the loss of her beloved Tammuz or Adonis.”[164]

The African travellers, R. and J. Lander, have given[165] a graphic account of what took place on the occasion of the eclipse of the Moon of Sept. 2, 1830, as witnessed by themselves:—“The earlier part of the evening had been mild, serene, and remarkably pleasant. The Moon had arisen with uncommon lustre, and being at the full, her appearance was extremely delightful. It was the conclusion of the holidays, and many of the people were enjoying the delicious coolness of a serene night, and resting from the laborious exertions of the day; but when the Moon became gradually obscured, fear overcame every one. As the eclipse increased they became more terrified. All ran in great distress to inform their sovereign of the circumstance, for there was not a single cloud to cause so deep a shadow, and they could not comprehend the nature or meaning of an eclipse.... Groups of men were blowing on trumpets, which produced a harsh and discordant sound; some were employed in beating old drums, others again were blowing on bullocks’ horns.... The diminished light, when the eclipse was complete, was just sufficient for us to distinguish the various groups of people, and contributed in no small degree to render the scene more imposing. If a European, a stranger to Africa, had been placed on a sudden in the midst of the terror-struck people, he would have imagined himself to be among a legion of demons, holding a revel over a fallen spirit.”

CHAPTER XIX.

ECLIPSES IN SHAKESPEARE AND THE POETS.

The sound of these words may be large but facts do not bear out the theory, for eclipses do not appear to have captivated our great poets to anything like the extent that Moon, Stars, and Comets have done.

Shakespeare has a few allusions to eclipses, but they are not of prime importance. In Macbeth we find:—

“And slips of yew
Shivered in the Moon’s eclipse”
—Act iv. sc. 1.

the precise meaning of which is not very obvious. “Shivered” of course means divided into pieces, but the idea intended is obscure.

The next quotation is more comprehensive and reflects more plainly the current of thought prevalent in Shakespeare’s day, albeit here again the word “eclipse” will be found to stand without much definite connection with what goes before. However the reader shall judge for himself:—

In King Lear we seem to come upon something very definitely historical, but I am not able to say what it is. The Earl of Gloster says:—

With this, Edmund, Gloster’s son, apparently agrees, for he exclaims:—

In Othello, the Moor of Venice himself, in a moment of excitement, says:—

In Anthony and Cleopatra we find Anthony expressing what our forefathers so often thought in connection with astronomical matters:—

Milton has an allusion to an eclipse of the Sun which possesses a two-fold interest—intrinsic and extrinsic. The former feature will be self-evident when the passage is read. The poet, in describing[166] the faded splendour of the fallen archangel, compares him to the Sun seen under circumstances which have temporarily deprived it of its normal brilliancy and glory:—

It has been well said by Dr. Orchard[167] that “this passage affords us an example of the sublimity of Milton’s imagination and of his skill in adapting the grandest phenomena of nature to the illustration of his subject.”

What I alluded to in saying that extrinsic interest attached to this quotation, is the fact that these lines might have caused the suppression of the poem as a whole. Mrs. Todd puts the matter thus:—“Paradise Lost was begun probably in 1658, although not finished until 1663, nor its thorough revision completed until 1665. The censorship still existed, and Tomkyns (one of the chaplains through whom the Archbishop gave or refused license), although a broader-minded man than many of his day, found this passage especially objectionable. The poem was allowed to see the light only through the interposition of a friend of Milton. Upon such slender chances may hang the life of an incomparable work of art! But it is easy to see that in the turbulent days when Charles the Second had returned to power, after the death of Cromwell, these lines should have been deemed dangerously suggestive, in imputing to monarchs ‘perplexity’ and ‘fear of change.’”

Other allusions to eclipses by Milton will be found as follows:—

Pope, in the following lines, may be presumed to mean that the covering up of the Sun by the Moon, during a total eclipse, results in the Moon becoming visible, at the cost of the Sun’s disappearance:—

I have not attempted to pursue this matter through the pages of our modern poets, but it is not unlikely that Scott and Tennyson (especially) would have something on the subject of eclipses.

CHAPTER XX.

BRIEF HINTS TO OBSERVERS OF ECLIPSES OF THE SUN.

A few words (they must be few for lack of space) may usefully be added, by way of advice, to persons proposing to choose a suitable locality at which to station themselves for viewing a total eclipse of the Sun. To begin with, of course they ought to get as close as possible to the central line, say within 10 or 20 miles at the most; this matter settled, the next important point is to find out where the duration of the totality will be longest, coupled with the Sun at its maximum elevation above the horizon (to escape the influence of mists and fogs). No advice, properly so-called, can be given on these points, because they depend on the special circumstances of every eclipse, and must be ascertained ad hoc from the Nautical Almanac.

In anticipation of a forthcoming eclipse, it is very important to know beforehand the probabilities of weather. If the locus in quo of an expected eclipse is in a civilised country, there will generally not be much difficulty in obtaining a certain amount of information as to this 6 or 12 months in advance. But inasmuch as total eclipses of the Sun, and often the best of them, are visible only in uncivilised countries or over trackless wastes, the problem becomes a complicated and anxious one. In such cases it is exceedingly desirable, where competent observers (including money) are available, that preliminary notes of weather should be made for a year or even two years in advance. There is in one sense no difficulty as to this, for all the mathematical local elements of every eclipse are always made public three or four years in advance through the pages of books like the Nautical Almanac, the Connaissance des Temps, the Berliner Jahrbuch, &c. One difficulty always confronts every eclipse expedition. If an out-of-the-way part of the world has to be visited, accessible by sea, transport from England, say, to the foreign shore is not usually a matter of difficulty, because Government ships are often placed at the disposal of astronomers. But the gravest difficulties often have to be faced after the arrival at the foreign shore, and for this reason. Every sea coast is, as a general rule applicable to the whole world, bad for astronomical observations. The problem then which has to be solved is, how best to get away from the coast inland to a high hill, and to find the means of transporting thither heavy packing-cases of instruments, personal luggage, creature comforts, and, if needs be, tents and the other accessories of camp life. Let not the reader of either sex take fright at the idea of sleeping under a tent. I speak with considerable experience when I say that, given fine or fairly fine weather, nothing is more enjoyable in a temperate climate. Under the term “creature comforts” I mean such things as tinned soups and preserved provisions which nowadays can so easily be purchased everywhere in England, and of such good quality. I would recommend these being taken even when the eclipse traveller expects to be lodged in the dwelling-places of civilised nations. Of course, if in order to see his eclipse he has to go into the wilds of America, Asia, or Africa, he must start fully equipped with all those personal impedimenta which will be found scheduled in the books mentioned in the footnote.[168]

CHAPTER XXI.

TRANSITS AND OCCULTATIONS.

No book professing to deal with eclipses would be complete without a few words of mention of “transits” and “occultations.” A transit is the passing of a primary planet across the Sun, or of a secondary planet (i.e. satellite) across its primary, whilst an occultation is the concealment of a star by the Moon, or of a secondary planet (i.e. satellite) by its primary. A little thought given to this definition will make it clear that a transit is essentially the same in principle as an eclipse of the Sun by the Moon—one body comes in front of another, and the former conceals in succession parts of the latter.

Practically the word “transit” in this connection is more especially applied to passages of the inferior planets, Mercury and Venus, across the Sun, or of the satellites of Jupiter across the disc of Jupiter, whilst the word “occultation” more particularly calls to mind the concealment of a star (apparently a little body) by the Moon (apparently a big body) or of a satellite of Jupiter (a little body) by Jupiter (a big body), the star and the satellite in each respective case passing behind the occulting body and being concealed for a shorter or longer time. Commonly the occulted body will remain hidden for an hour or two, more or less. In the case of Jupiter the satellites of that planet may also, on occasions, be seen to undergo eclipse in the shadow cast by Jupiter itself. An eclipse of a Jovian satellite is therefore on all fours in principle the same as an eclipse of the Moon, caused, as we know, by the Moon passing for a short time into the dark shadow cast by the Earth. The conditions just laid down in respect of Jupiter and its satellites also find a counterpart in the case of the satellites of Saturn, but whilst these phenomena are incessantly occurring and visible in the case of Jupiter, they are exceedingly rare in the case of Saturn owing to its greater distance and the difficulty of seeing most of its satellites because of their small apparent size.

Having regard to the circumstance that transits of Mercury and Venus only happen at intervals of many years, it is not worth while for the purposes of this work to devote any great amount of space to them. In point of fact, whilst the next three transits of Mercury are as remote as 1907, 1914 and 1924, there will be no transit of Venus at all during the 20th century; not another indeed until A.D. 2004.

From the standpoint of an amateur astronomer the various phenomena which attend the movements of the satellites of Jupiter, constitute an endless variety of interesting scenes, which are the more deserving of attention in that they can be followed with the aid of a telescope of very moderate size and capabilities.[169]