Whatever the reason, Dante’s fifty-one references to the moon are in strong contrast to his allusions to the sun. These are four times as many, and they include warm expressions of admiration and delight, and beautiful epithets and similes. The sun is Titan with his chariot and horses,[194] he is a Mirror, a Car of Light, the Lantern of the World, the Prince of the Stars, the Father of all mortal life.[195] His beautiful form is admired, “la perfetta sua bella figura,”[196] and his intense brilliance often noted.[197] He is the guide that leads all aright,[198] to whom Virgil appeals:—

Under his rays the rose expands, the air is gladdened, mists are dispelled, snow melts, and all things are quickened into life.[200] Unlike the moon, the sun is the bringer of warmth and comfort, chasing away cold and darkness,[201] sunrise is the hour of renewed hope and confidence,[202] it strengthens our limbs, paralysed by the cold of night,[203] it is eagerly awaited through the darkness by the little bird on her nest;[204] and delicate flowers, bowed and closed during the cold night, rise upright on their stems and open as soon as the sun shines once more upon them.[205] The exquisite sunsets and sunrises of the Purgatorio are favourite passages with all readers.

Love is compared with the summer sun,[206] the generosity of a noble nature resembles “the great planet.”[207] The Emperor Henry VII., from whom Dante expected the regeneration of Italy and the whole Christian world, is likened to the rising sun;[208] the birth of St. Francis is described as “nacque al mondo un sole,”[209] and his birthplace ought rightly to be called not Assisi but Orient.[210] Virgil is addressed as “O Sol che sani ogni vista turbata;”[211] Beatrice is “Il sol degli occhi miei.”[212] Finally the sun is the best symbol of God,[213] and so it is used many times in the Divine Comedy: “Il Sol degli angeli,”[214] “Il Sol che raggia tutto nostro stuolo;”[215] a spirit turns to “il Sol che la riempie,”[216] and when Virgil laments that he is shut out of heaven it is in these words: “Ho i’ perduto Di veder l’ alto Sol che tu disiri.”[217]

But we may not dwell on those thoughts of the sun as the typical giver of light and life; we must ask what Dante says about his movements, since this was the chief subject-matter of mediæval astronomy.

His daily course, “il cammin del Sole,”[218] is often spoken of, and is indicated both by his position in the sky, and the length and direction of shadows. The second Eclogue begins with a description of a breathlessly hot midday, when objects, which are usually shorter than their own shadows, now surpassed them in length.

At this time the sun appears most brilliant, and seems to move most slowly, since he is scarcely changing his position with regard to the horizon.

The greatest number of references to the sun’s daily journey occur in the Purgatory, and we shall quote them in a later chapter.

His yearly journey through the zodiac is also very often referred to. When relating his first meeting with Beatrice, Dante names his age, not by simply saying that he was nearly nine years old, but by counting the number of the times that the “heaven of light,” that is, of the sun, had returned to the same point since his birth:—

“Nove fiate già, appresso al mio nascimento, era tornato lo cielo della luce quasi ad un medesimo punto, quanto alla sua proprio girazione.”[220]

The sun’s “own revolution” is of course its apparent yearly movement, as distinct from the diurnal movement which it shares with all the heavenly bodies.

The same thought is expressed in a sonnet:

We know further that Dante was born in either May or June, because he says, when he finds himself among the stars of Gemini, that the sun was rising and setting in this sign at the time of his birth.[222]

Boccaccio tells us that a Mayday feast, given by the father of Beatrice, was the occasion of Dante’s first meeting with her, and also that not long before his death in Ravenna he told a friend that he had completed his fifty-sixth year in the preceding May, so we may conclude that May was the month of his birth.

Dante seems to have taken some trouble to find out the exact period of the sun’s revolution. His text-book, the Elementa of Alfraganus, only gives it as 365¼ days nearly:—“Sol ... orbem confecit diebus 365 et propè ¼.” Ristoro d’Arezzo and Brunetto Latini were content to repeat this rough estimate, and call the year 365 days 6 hours, but Dante wished to be more exact, and somehow contrived to obtain a value which was much nearer the modern estimate of 365 days, 5 hours, 48 minutes, 46 seconds. We know this from two passages. In the Convivio he gives the half period as less than 182 days 15 hours; and in the Paradiso Beatrice says that January will in time cease to be a winter month, because of a neglected fraction of time.

January was in fact receding from the winter, and steadily though slowly advancing towards the spring, because the Julian year (as we saw, p. 171) was 11 minutes 14 seconds longer than the true solar tropical year. When Julius Cæsar reformed the Calendar, March 25 was made (as of old) to coincide with the spring equinox, but by Dante’s time this date was 13 days late, and the true equinox fell on March 12. Consequently though the day called January 1 still came 84 days before March 25, it was only 71 days before the spring equinox.

If Beatrice meant to speak with scientific precision, and was correct in her hundredth part of a day per annum, that is, if the difference between the astronomical and the Julian year was one day in a hundred years, it would be 7100 years before the first of January came to coincide with the spring equinox, and January became a spring month. But the error quoted is really rather too large, for a hundredth part of a day is 14 minutes 24 seconds, and it was in fact only 11 minutes 14 seconds.

It would be interesting to know where Dante found this value, which is practically the only astronomical datum not given in Alfraganus. Ptolemy, following Hipparchus, had given the tropical year as ¹/₃₀₀ part of a day less than 365¼; Albategnius gave a more accurate figure, and one which agrees well with the “centesma,” for his tropical year differs from the Julian by a little less than ¹/₁₀₆ of a day; but he also improved the value of precession, and Dante does not seem to have known this, so he was probably not acquainted with this astronomer’s work. The Alfonsine Tables gave a value which was very close indeed to the correct one, making the tropical year only 30 seconds longer than the modern value, and the difference between the Julian and true year ¹/₁₃₄ of a day. (The correct value is ¹/₁₂₈). Either of these figures may have been known to Dante indirectly: perhaps he had obtained the Alfonsine value in conversation with Brunetto Latini, who had visited Alfonso’s court. His fraction was evidently only approximate, but it is interesting to know that he had found out more than popular books could tell him about the period of the sun’s revolution, and that he had been sufficiently struck by the small difference between the calendar and astronomical years to mention it in a picturesque way in his poem. It is possible that he had heard of Roger Bacon’s appeal to the Pope in 1267 to correct the calendar because the date of the spring equinox was of importance in connection with the observation of Easter.

It is hardly necessary to remind my readers that this was done by another Pope three hundred years later, before January had made much more advance towards becoming a spring month. The hundredth part of a day, of which Beatrice complained, is now subtracted from the year by omitting to make century years leap years; but as the error was really not quite so great as she said, an exception is made for century years divisible by 400. Thus 1600 was a leap year, but not 1700, 1800, or 1900.

Dante seems to have connected any season of the year with the sun’s path in the zodiac as readily as with the name of a month. The sun’s yearly course through the signs is shown diagrammatically in figure 40, and a glance at this will make clear a number of allusions without any explanation.

Starting from the first point of Aries at the spring equinox, which in Dante’s time fell in the middle of March, and taking one-twelfth of the year to traverse each sign, it is evident that during the end of March and beginning of April the sun was in Aries; he entered Cancer and reached the summer solstice in June, the autumnal equinox in Libra in September, and the winter solstice when he entered Capricornus in December. The six signs above the horizontal line are northern, the six below are southern.

The following are a few typical examples.

When Dante wishes to express the transition of his feelings from despondency to courage, at seeing the stern and troubled face of his guide melt suddenly to a smile, he compares himself to a poor shepherd who wakes early and sees the fields covered, as he thinks, with snow, but in a short time finds that it is only hoar-frost which has put on the semblance of her white sister, and seeing the face of the world changed he gladly leads out his sheep to pasture. The time at which this may happen is

That part of the youthful year when the sun cools his locks beneath Aquarius is clearly the end of January or beginning of February, but the last line may bear one of two meanings. If we translate “mezzodì” as “half the day” it means that the nights are growing shorter, and very soon (in March) when the sun will have reached the equinox, they will be just twelve hours long. If we take “mezzodì” as meaning “the south,” we must interpret the passage in the light of others in the Divine Comedy where Night is personified, and considered as circling in the zodiac always opposite to the sun. For instance in Purg. ii. 1-6 (a passage which will be more fully explained later) Night is described as circling opposite to the sun, “La notte, che opposita a lui cerchia,”[226] and as the sun at that time was in Aries, Night was in Libra, “le Bilance.” Henceforth for six months the sun will be in the northern signs, and the days longer than the nights, but as soon as Night begins to assert her supremacy, and the nights begin to be longer than the days, the sun enters Libra and then it is not visible all night. This is the meaning of

When Night becomes dominant, the Scales fall from her hand, for the sun is in that sign.

Applying this idea to the passage quoted above, it will mean “The nights are going southward,” for the sun in Aquarius is not far from the point where he crosses the equator to the north, therefore Night circling opposite to him is nearing the point where she goes south. Either interpretation is faithful to fact, but perhaps the circumstance that the plural noun is used favours the first.

Conrad Malaspina prophesied to Dante that his favourable opinion of the Malaspina family would be justified “before the sun had come to rest again seven times in the bed which the Ram covers and bestrides with his four feet.”

The sun was at the time in the Ram, and Malaspina means that less than seven years would elapse, before his prophecy was fulfilled. The aptness of the description may be seen by the figure of Aries as portrayed in an old seventeenth century book in which the Ram is uncomfortably trying to sit on the ecliptic.

Another instance is in the beautiful midwinter Ode, “Io son venuto al punto della rota.”[229] Each stanza pictures a feature of a severe winter—snow and rain, the absence of summer birds, bare trees and dead flowers, the favourite walk become a torrent; but the first describes the position of stars and planets. When the sun sets, the Twins appear on the eastern horizon, hence we know at once that the sun is in Sagittarius and the time is November or December. To confirm his melancholy, the poet adds that the Star of Love (Venus) is hidden from us by the sun’s rays which now shine athwart her, and that the planet which strengthens the cold (Saturn, the “frigida stella” of Virgil) displays himself in that arc of the sky in which all the seven planets cast the shortest shadow;[230] that is, either he is on the meridian at sunset, or he is in the most northerly part of the zodiac, in Gemini or Cancer. A planet in this place, as for instance the sun at midsummer, is visible longer, describes a longer arc, and casts shorter shadows, than in any other part of the zodiac. And as this is the part which rises over the eastern horizon as the sun sets, Saturn would also rise at that time and remain visible all night.

The opening lines of the Ode run thus:—

It is astonishing that Giuliani should so completely miss the point of the “twinned sky,” that he substitutes “ingemmato” for “geminato,” and reads—

He understands the hour of evening to be meant, when the Wheel of Day and Night brings a jewelled, i.e. starry sky on the horizon as the sun sets. But it is not only on the horizon that stars appear at sunset; and the mention of Gemini to indicate the time of year is thoroughly characteristic of Dante. The Wheel is the revolving year which has carried the sun into Sagittarius.

Angelitti remarks that the whole description was literally true for December 1296, since Venus was then in conjunction with the sun, and Saturn in Cancer;[233] and as this poem is a complaint of the hardness of his lady, to whom the poet is nevertheless wholly devoted, it may well have been written in that time when the lady Philosophy refused to smile upon her lover.[234]

Further on in the same poem the effects of the sun in spring, when he is in the sign of Aries, are alluded to as “the virtue of Aries”:—

Contrast with this the passage in the Paradiso where “nocturnal Aries” is used as a synonym for autumn.

For although Aries may be seen during some part of the night in the greater part of the year, it is most emphatically a noctural sign when it rises as the sun sets, and remains above the horizon until he rises; this happens when the sun is in the opposite sign of Libra, which he enters at the autumnal equinox.

A rather curious passage in the Paradiso is incomprehensible unless we think of the sun’s path in the zodiac, and realize that Dante is comparing the brightness of the spirit of St. John in an indirect way with the brightness of the sun.

If a light as dazzling as this spirit were to shine forth in Cancer, there would be perpetual day for a whole month in winter. For when the sun entered Capricornus, which he does in December, he would be exactly opposite, so that as one light set the other would rise, and there would be no darkness until the sun passed into another sign.

To many similar instances the diagram (p. 276) will be found to supply a key, and some we shall have occasion to notice presently in another connection.