recorded observations Peters computed | parallax of 0.39 of a second (about a an orbit for the supposed companion, mean of the results found by Drs. and found a period of about fifty years. Elkin and Gill), the distance of Sirius Safford also investigated the problem, would be 528,884 times the sun's disand announced in 1861 the probable tance from the earth, a distance which position of the invisible companion. light would take about eight and oneAbout four months after the publica- third years to traverse. tion of Safford's results, Mr. Alvan Knowing the distance of Sirius from Clark, the famous American optician, the earth, and its annual proper motion, observing with a telescope of 18 inches it is easy to calculate its actual velocity aperture, detected a small star near in a direction at right angles to the line Sirius, the position of which agreed of sight. This comes out about ten closely with that of Safford's hypothet- miles a second. The spectroscope ical companion. Here was a case some-shows that Sirius has also a motion in what similar to the discovery of the the line of sight, and hence its real planet Neptune - the prediction, by velocity through space must be greater mathematical analysis, of the existence than that indicated by its proper moof a celestial body previously unknown tion. In the year 1864 observations by to astronomers. Numerous observa- Dr. Huggins showed that Sirius was tions of this small star have been made receding from the earth at the rate of since its discovery, and there is now twenty-nine miles a second. Some no doubt that it is revolving round its years afterwards careful measures of brilliant primary. That the observed the star's spectrum showed that this irregularities in the proper motion of motion had ceased; subsequent measSirius are wholly due to the influence ures showed that the motion was reof this companion seems, however, to versed, and recent observations by Dr. be still an open question. Several Vogel indicate unmistakably that the orbits have been computed, most of motion has now been changed into a which assign a period of forty-nine or motion of approach! It seems difficult fifty years; but an orbit recently com- to understand how this curious change puted by the present writer gives a in the direction of the star's motion can period of about fifty-eight and one-half be accounted for otherwise than by years, and Howard finds a period of orbital movement; in the same way fifty-seven years. Burnham, however, that the planet Venus is sometimes thinks that fifty-three years is probably nearer the truth. As the companion has now approached Sirius so closely as to be invisible with even the giant telescope of the Lick Observatory, some years must elapse before the exact length of the period can be definitely settled. The great brilliancy of Sirius has naturally suggested proximity to the earth, and modern measures of its distance have confirmed the accuracy of this idea. The most reliable determinations of its parallax (or the angle subtended by the radius of the earth's orbit at the place of the star) make it about four-tenths of a second of arc, and places it about fourth in order of distance from the earth. Assuming a approaching the earth and sometimes receding from it, owing to its orbital motion round the sun. The motion may possibly be due to the existence of some invisible close companion. the Placed at the distance of Sirius, Sun would, I find, be reduced to a star of only the third magnitude, or about four magnitudes fainter than Sirius appears to us. This indicates that Sirius is about forty times brighter than the Sun would be in the same position, and would imply that Sirius is a far more massive sun than ours. assume the same intrinsic brilliancy of surface and the same density for both (parallax 0-76 of a second), 61 Cygni (0-45′), and Lalande 21,185, for which Kapteyn found a parallax Herculis a parallax of 0'40" was found by Belopolof 0-434", and Winnecke 0.5". For the star Eta If we sky and Wagner; but this does not seem to have 1 The three nearest stars are: Alpha Centauri been confirmed by any other astronomer. bodies, the above result would make | proper motion of Sirius, that the comthe diameter of Sirius 6·32 times the panion is about one-half the mass of the Sun's diameter, and its mass no less primary, and equal in mass to our sun ! than two hundred and fifty-three times It must, therefore, be nearly a dark the mass of the Sun. As, however, the body. It has been suggested that the intrinsic brightness of the surface of companion may possibly shine by reSirius and its density, or specific grav- flected light from Sirius in the same ity, may differ widely from those of the way that the planets of the solar sysSun, these calculations are of course tem shine by reflected light from the open to much uncertainty. The light Sun. Some calculations which I have of Sirius, analyzed by the spectroscope, recently made show, however, that this differs considerably from the solar light, hypothesis is wholly untenable. Asand the strong development of the suming, with Auwers, that the mass hydrogen lines in the star's spectrum and diameter of the companion are denotes that Sirius is, in its chemical equal to those of the Sun, I find that the constitution, not comparable with our companion would, if illuminated solely sun. It may possibly be very much by reflected light from Sirius, shine as a hotter and therefore smaller in diam- star of only sixteen and a half magnieter and mass than the figures given tude. A star of this magnitude - about above would indicate. Fortunately we the faintest visible in the great Lick can find the mass of a binary or revolv- telescope-placed close to a brilliant ing double star by another and more star like Sirius would, even when most certain method. Knowing the orbit of favorably situated, be utterly invisible the star and its distance from the earth, in our largest telescopes. If its mass is we can calculate the combined mass of much less than one-half that of Sirius the components in terms of the Sun's as its faintness would seem to sugmass. Making the necessary computa- gest-it is possibly a comparatively tions for Sirius, I find that the com- small body, and the reflected light from bined mass of Sirius and its companion its primary would be proportionately is a little over three times the mass of less. It seems clear, therefore, that the Sun, and the mean distance between the companion must shine with some them twenty-two times the Sun's dis- inherent light of its own, otherwise it tance from the earth, or a little more could not possibly be so bright as the than the distance of the planet Uranus tenth magnitude. It is probably a sun from the Sun. This result-recently of small luminosity revolving round confirmed by Dr. Auwers's calculations Sirius in the same way that the comwould imply that Sirius is intrinsi-panions to other binary stars revolve cally a much brighter sun -surface for round their primary. The disparity in surface than ours, and that "the mon- brightness is, however, remarkable, no arch of the skies" is a "giant " only other binary star showing so great a in appearance; the greater brightness difference in the brilliancy of the comof its surface and its comparative prox-ponents. imity to the earth accounting for its great apparent brilliancy. As I have said above, the Sun, if placed at the distance of Sirius, would shine as a star of the third magnitude. There is, therefore, a difference of seven stellar magnitudes between the light of the Sun and that of the Sirian satellite. This implies that the light emitted by the Sun is six hundred and thirty-c 7-one times greater than that radiated by the companion of Sirius. If of the same intrinsic brightness of surface, 1 Journal of the British Astronomical Associa tion, Maroh, 1891. this be now precisely true or not, it cer tainly was so at the time when Hallam wrote; and this by itself constitutes a great claim on our attention. the latter would, therefore, have a diameter about one twenty-fifth of the Sun's diameter, or thirty-four thousand miles. But if of the same mass as the Sun, its density with this small diameter There is of course a certain class of would be enormous in fact, vastly readers to whom it is quite unnecessary greater than we can imagine possible to introduce Ariosto, and there is probfor any body, large or small. Indeed, ably no one to whom his name, and the if we suppose its diameter to be one-half general character of his work, can be at that of the Sun, its density would be all unfamiliar. The great light of the 11.52 (1.44×8), or about equal in den-age of Leo X., or in other words, of the sity to lead, and it seems very improb- Renaissance that immediately preceded able that a self-luminous body could the Reformation, writing the Italian have so high a density as this. We language in its perfection; lucid where must conclude, therefore, that the sat- Dante had been obscure; bright and ellite of Sirius is a comparatively large sparkling where Tasso after him was body having a small intrinsic bril-grave and stately; a model to Spenser, liancy of surface-possibly a cooling the poets' poet of England, and therebody verging towards the utter extinc- fore contributing an important element tion of its light. If this be so, it will probably, in the course of ages, disappear altogether from telescopic vision, and its continued existence will only be known by its influence on the motion of Sirius. to the history of our literature, so that Walter Scott, often called the Ariosto or Wizard of the North, learnt from him how to construct a kaleidoscopic. narrative, and to charm with "a shifting brilliancy and witchery of color," a poet of whom such things as these can be said, should surely be a household word among us. If there are any planets revolving round Sirius they will probably remain forever unknown to us. A planet comparable with Jupiter in size would be To a public that wants to be amused, utterly invisible in the giant telescope that is eager for literary delicacies, and of the Lick Observatory, or even with for sensational and exciting stories, an instrument very much larger. I am that runs here and there for meat and disposed, however, to think that these grudges if it be not satisfied, Ariosto binary stars may perhaps form excep- should, one would think, supply the tions to the general rule of stellar sys- very article that it wants. Read in the tems, and that single stars, like our original language, he is a perfect storesun, more probably form the centres of house of beauty and attractive interplanetary systems like our own. Or est; and any one who knows Latin or possibly the reverse of this may be French, or both, can easily master true, the single stars forming the ex- enough Italian for the purpose. And ceptions and binary stars the rule. In either case we may conclude, I think, judging from the analogy of our sun, that single stars are more likely to have planets revolving round them. if any should be led by this paper to The events of a siege have often sup Ariosto is, in the first place, a great story-teller and humorist. If the pub-plied the ground for an epic poem, such Ladies, and knights, and arms, and love's fair flame, Deeds of emprise and courtesy, I sing, What time the Moors from sultry Afric came lic likes short stories well told, there is as those of which the interest circles a mass of them here. If it prefers a round Troy, Jerusalem, and Granada. continuous novel with an artfully ar- The old chroniclers had left accounts of ranged plot, the "Orlando " as a whole a perfectly mythical siege of Paris by is such a work. If it desires to be the Saracens in the time of Charlemagne made to laugh, or at least to indulge in a and his Paladins. It is the outline of grim, internal chuckle, the poem is this which is traced in the opening lines brightened up from first to last by an of the "Orlando," and translated by under-current of sub-acid humor, intan-Frank Osbaldistone, as all the world gible as the humor of Sterne, but on the knows, into the unwilling ears of Di whole far purer, caricaturing chivalry Vernon. in a somewhat Cervantic manner, but yet not burlesquing it as it is burlesqued in "Don Quixote," using supernatural agencies with the same effect of changeful color and painted mirage as we find in the "Rape of the Lock," with something of Pope's sarcastic deference to women, but yet not continuously ironical nor by any means without serious meaning. And there are those who will be especially attracted by the fact, that while each canto is prefaced by general observations of a practical and worldly-wise character, there is no deliberate attempt to philosophize, nor any touch of Dickens's "determined but doubtful pathos." The story is told for its own sake, and the writer, as has been said of Macaulay, communicates the interest which he feels himself. But Ariosto is not only a poet and novelist; he is, if not a historian, at least the author of a work which throws great light on mediæval history. His plot is laid in the eighth century, but his ideas and local coloring are those of his own time, and between the two he helps us to realize, what English history by itself would hardly suffice to impress upon us, that the early history of modern Europe bases its romantic interest on a very real and grim contingency, the continual possibility that the Crescent might drive out the Cross from the whole of the civilized world. In Ariosto's own time, if the unbelievers had been driven out of Spain, they had established themselves in and around Constantinople, and were feared and respected no less than the most valiant and civilized Christians. Led on by Agramant, their youthful king, O'er the broad waves, in France to waste and war, And menaced Christian Charles, the Ro man emperor. In the original : Le donne, i cavalier, l' arme, gli amori, Seguendo l' ire e i giovenil furori Di vendicar la morte di Trojano It is worth while observing that the first two lines suggested to Dryden the plot of the "Conquest of Granada,” and to Scott, in all probability, his romantic handling of "Ivanhoe." Also, that the peculiar lilt of the stanza was well caught by Shakespeare in the burlesque lines declaimed by his Don Adriano de Armado : The armipotent Mars, of lances the almighty, Gave Hector a gift, the heir of Ilion a; A man so breathed, that certain he would fight, yea From morn till night, out of his pavilion. This mythical siege of Paris, with its supernatural episodes, cannot but suggest to us that modern nations have actually preferred fiction to fact as a starting point for their national histories. The fables which form the prelude to the annals of Greece and Rome were of natural and spontaneous | powers of whose celebrated horn are growth, and are indistinguishably known to most people, is the Prince of blended with the facts in immediate Wales of the period. Gunpowder has sequence to them. It would seem that just been discovered, and, like all new the English people deliberately chose inventions, does not find favor in the the Arthurian legend as a preface to eyes of the poet; Ariosto views guntheir own records ; but at least they powder much as Mr. Ruskin views filled up with it a space of time which, railways. The writer, who revels in though within the limits of general flying horses, enchanted shields, and so history, is nearly a blank as regards forth, as the machinery of warfare. Britain itself. If they had attached the cannot abide the thought of what was a Arthurian fables to the name of Alfred, real and very wonderful invention. To and insisted on supplanting by means descend from the clouds on a hippoof them the authentic history of Al-griff, to blind the enemy with the glitfred's reign, they would have done ter of your magic shield, or stun him nearly what the continental chroniclers with the terrific noises of your horn, is did, when, in the place of a real Charle-legitimate and respectable, but to aim a magne and of real facts recorded by gun at your foe is an act that may by no Eginhard and others, they foisted a means be endured. fictitious Charlemagne as the centre of a cycle of impossible stories, and then obtained the authority of the See of Rome for erecting the acceptance of famous Paladin, gives Ariosto's poem them into a pious opinion. The wrath of Achilles furnished a kind of title-heading for the Iliad. The madness of Orlando, or Roland, that its name, and indicates it as carrying on the story of Boiardo's "Orlando Innamorato." But the coquetry of Angelica and its dire effects upon Roland furnish hardly more than a series Indeed, the French and British myths are recognized as so closely akin, that Ariosto transfers the name and prophetic power of Merlin into the substance of his story, and makes of episodes. The real hero is RugCharles's Paladins a close parallel to giero, or Roger, described, like Drythe Knights of the Round Table. It is den's Almanzor, as a valiant Saracen to be feared that the men of old, like warrior, who becomes a Christian for some of their descendants, much pre- the love of Bradamante, the real ferred the beautiful to the true. heroine of the epic, and a very interThe historical value of the "Or-esting one to boot, who goes about in lando" lies in the fact of its being in armor and fights as bravely as any many respects a gigantic anachronism. knight-errant, but is with it all as pure The events are placed in the eighth and noble a Frankish lady as can be century, but their theatre is essentially read of anywhere. The main line of the Europe of Ariosto's own time, human interest throughout the book except so far as the Saracens are supposed to occupy it. Italian unity is not referred to; but the golden lilies of France, the gigli d'oro, are the object of Ariosto's loyalty, and the centre of a great Christian confederacy, including the whole west and north-west of Europe. Among the associated states, England and Scotland, as fully formed to be in the presence of such enslavers as completely civilized, and as highly as Alcina and Angelica. But Bradaconsidered as any others, play a con- mante quietly rectifies the resulting sitspicuous part, with London and St. uations in a philosophical spirit entirely Andrews for their respective capitals, her own, until her devotion is rewarded and take their full share in the defence in the last canto by a union with Rugof Paris. Astolpho, the knocking-down giero, at the time of Charlemagne's lies in the series of scrapes into which Ruggiero gets himself, and the persevering, and it must be said forgiving, manner in which Bradamante continually extricates him. Ruggiero, although a fairly constant lover according to the ideas of that time and country, is somewhat weaker than he ought |