But there is present, too, in spite of all obstacles and defeats, an undying hope that somehow—by prayers and sacrifices to the celestial powers, or by the choice of astrologically favorable times of doing things—that somehow the course of human lives, mapped out at birth by the stars under the control of relentless destiny, may be altered. So the characters in Chaucer’s poems pray to the orbs of the sky to help in their undertakings. The love-lorn Troilus undertakes scarcely a single act without first beseeching some one of the celestial powers for help. When he has confessed his love to Pandarus and the latter has promised to help him, Troilus prays to Venus:
“‘Now blisful Venus helpe, er that I sterve,Of thee, Pandare, I may som thank deserve.’”[169]
and when the first step has been taken and he knows that Criseyde is not ill disposed to be his friend at least, he praises Venus, looking up to her as a flower to the sun:
“But right as floures, thorugh the colde of nightY-closed, stoupen on hir stalkes lowe,Redressen hem a-yein the sonne bright,And spreden on hir kinde cours by rowe;Right so gan tho his eyen up to throweThis Troilus, and seyde, ‘O Venus dere,Thy might, thy grace, y-heried be it here!’”[170]
When Troilus is about to undertake a step that will either win or lose Criseyde he prays to all the planetary gods, but especially to Venus, begging her to overcome by her aid whatever evil influences the planets exercised over him in his birth:
“‘Yit blisful Venus, this night thou me enspyre,’Quod Troilus, ‘as wis as I thee serve,And ever bet and bet shal, til I sterve.And if I hadde, O Venus ful of murthe,Aspectes badde of Mars or of Saturne,Or thou combust[171]or let were in my birthe,Thy fader prey al thilke harm disturne.’”[172]
Troilus does not forget to praise Venus when Criseyde is won at last:
“Than seyde he thus, ‘O, Love, O, Charitee,Thy moder eek, Citherea the swete,After thy-self next heried be she,Venus mene I, the wel-willy planete;’”[173]
And after Criseyde has gone away to the Greeks, it is to Venus still that the lover utters his lament and prayer, saying that without the guidance of her beams he is lost:
“‘O sterre, of which I lost have al the light,With herte soor wel oughte I to bewayle,That ever derk in torment, night by night,Toward my deeth with wind in stere I sayle;For which the tenthe night if that I fayleThe gyding of thy bemes brighte an houre,My ship and me Caribdis wol devoure:’”[174]
Another effect of astrological faith on conduct was the choice of times for doing things of importance with reference to astrological conditions. When a man wished to set out on any enterprise of importance he very often consulted the positions of the stars to see if the time was propitious. Thus in theSquieres Taleit is said that the maker of the horse of brass
“wayted many a constellacioun,Er he had doon this operacioun;”[175]
that is, he waited carefully for the moment when the stars would be in the most propitious position, so that his undertaking would have the greatest possible chance of success. Pandarus goes to his niece Criseyde to plead for Troilus at a time when the moon is favorably situated in the heavens:
“And gan to calle, and dresse him up to ryse,Remembringe him his erand was to doneFrom Troilus, and eek his greet empryse;And caste and knew in good plyt was the mone—To doon viage, and took his wey ful soneUn-to his neces paleys ther bi-syde.”[176]
The kind of fatalism that Chaucer’s characters, as a rule, represent is well illustrated in the story of Palamon and Arcite, told by the Knight in theCanterbury Tales. These two young nobles of Thebes, cousins by relationship, are captured by Theseus, king of Athens, and imprisoned in the tower of his palace. From the window of the towerPalamon espies the king’s beautiful sister Emelye walking in the garden and instantly falls in love. Arcite, seeing his cousin’s sudden pallor and hearing his exclamation which, Chaucer says, sounded
“As though he stongen were un-to the herte.”[177]
thinks that Palamon is complaining because of his imprisonment and urges him to bear in patience the decree of the heavens:
“‘For Goddes love, tak al in pacienceOur prisoun, for it may non other be;Fortune hath yeven us this adversitee.Som wikke aspect or disposiciounOf Saturne, by sum constellacioun,Hath yeven us this, al-though we hadde it sworn;So stood the heven whan that we were born;We moste endure it; this is the short and pleyn.’”[178]
This is the doctrine of Necessity, and it suggests the Stoic virtue of submission to fate; yet Arcite’s attitude toword his misfortune is not truly stoic, for there is none of that joy in submission here that the Stoic felt in surrendering himself to the will of the powers above. Arcite would resist fate if he could.
Palamon explains the cause of his woe and when Arcite looks out and sees Emelye he too falls a victim to love. Then Palamon knits his brows in righteous indignation. Did he not love the beautiful lady first and trust his secret to his cousin and sworn brother? And was it not Arcite’s duty and solemn pledge to help and not hinder him in his love? Arcite’s defence shows that the fatalism that dominates his thought is a fatalism that excuses him for doing as he pleases: Love knows no law, but is a law unto itself. Therefore he must needs love Emelye.
“Wostow nat wel the olde clerkes sawe,That ‘who shal yeve a lover any lawe?’Love is a gretter lawe, by my pan,Than may be yeve to any erthly man.And therefore positif lawe and swich decreeIs broke al-day for love, in ech degree.A man moot nedes love, maugree his heed.”[179]
When Arcite is released from prison but banished from Athens with the threat of death should he return, both men are utterly unhappy, Arcite, because he can no longer see Emelye, and Palamon because he fears that Arcite will return to Athens with a band of kinsmen to aid him, and carry off Emelye by force. After Arcite has gone Palamon reproaches the gods for determining the destiny of men so irrevocably without consulting their wishes or their deserts:
“‘O cruel goddes, that governeThis world with binding of your word eterne,And wryten in the table of athamauntYour parlement, and your eterne graunt,What is mankinde more un-to yow holdeThan is the sheep, that rouketh in the folde?’”[180]
Many a man, Palamon says, suffers sickness, imprisonment and other misfortunes unjustly because of the inexorable destiny imposed upon him by the gods. Even the lot of the beasts is better, for they do as they will and have nothing to suffer for it after death; whereas man must suffer both in this life and the next. This, surely, is not willing submission to fate.
After some years Palamon escapes from prison and encounters Arcite, who has returned in disguise and become Theseus’ chief squire. They arrange to settle their differences by a duel next day. But destiny was guiding Theseus’ conduct too, so the narrator of the story says, and was so powerful that it caused a coincidence that might not happen again in a thousand years:
“The destinee, ministre general,That executeth in the world over-alThe purveyaunce, that God hath seyn biforn,So strong it is, that, though the world had swornThe contrarie of a thing, by ye or nay,Yet somtyme it shal fallen on a dayThat falleth nat eft with-inne a thousand yere.For certeinly, our appetytes here,Be it of werre, or pees, or hate, or love,Al is this reuled by the sighte above.”[181]
Theseus goes hunting and with him, the queen and Emelye. They of course interrupt the duel between Palamon and Arcite. Through the intercession of the two women the duelists are pardoned and it is arranged that they settle their dispute by a tournament set for about a year later.
On the morning before the tournament Palamon, Arcite, and Emelye all go, at different hours, to pray and sacrifice to their respective patron deities. The times of their prayers are chosen according to astrological considerations, each going to pray in the hour[182]that was considered sacred to the planet with which his patron deity was identified. Palamon prays to Venus only that he may win his love, whether by victory or defeat in the tournament makes no difference to him. After his sacrifices are completed, the statute of Venus shakes and Palamon, regarding this as a favorable sign goes away with glad heart. Arcite prays Mars for victory and is answered by a portent even more favorable than that given to Palamon. Not only does the statue of Mars tremble so that his coat of mail resounds, but the very doors of the temple shake, the fire on the altar burns more brightly and Arcite hears the word “Victory” uttered in a low dim murmur. Emelye does not want to be given in marriage to any man and so she prays to Diana[183], as the protectress ofmaidenhood, to keep her a maid. Diana, the goddess, appears in her characteristic form as a huntress and tells Emelye that the gods have decreed her marriage either to Palamon or to Arcite, but that it cannot yet be revealed to which one she is to be given.
But now there is trouble in heaven. Venus has promised that Palamon shall have his love, and Mars has promised Arcite the victory. How are both promises to be fulfilled? Chaucer humorously expresses the dilemma thus:
“And richt anon swich stryf ther is bigonneFor thilke graunting, in the hevene above,Bitwixe Venus, the goddesse of love,And Mars, the sterne god armipotente,That Iupiter was bisy it to stente;Til that the pale Saturnus the colde,That knew so manye of aventures olde,Fond in his old experience an art,That he ful sone hath plesed every part.”[184]
We had almost forgotten that all the gods to whom prayers have been uttered and sacrifices offered were anything more than pagan gods. But now, by the reference to Saturn, “the pale Saturnus the colde” suggesting the dimness of his appearance in the sky, we are reminded that these gods are also planets.
But, to resume the story, Saturn finds the remedy for the embarrassing situation. He rehearses his powers and then tells Venus that her knight shall have his lady, but that Mars shall be able to help his knight also.
“‘My dere doghter Venus,’ quod Saturne,‘My cours, that hath so wyde for to turne,Hath more power that wot any man...........Now weep namore, I shal doon diligenceThat Palamon, that is thyn owne knight,Shal have his lady, as thou hast him hight.Though Mars shal helpe his knight, yet natheleesBitwixe yow ther moot be som tyme pees,Al be ye noght of o complexioun,That causeth al day swich divisioun.’”[185]
When the appointed time for the tourney arrives, in order that no means of securing the god’s favor and so assuring success may be left untried, Arcite, with his knights, enters through the gate of Mars, his patron deity, and Palamon through that of Venus. Palamon is defeated in the fight but Saturn fulfills his promise to Venus by inducing Pluto to send an omen which frightens Arcite’s horse causing an accident in which Arcite is mortally injured. In the end Palamon wins Emelye.
Although the scene of this story is laid in ancient Athens, the characters are plainly mediaeval knights and ladies. Throughout the poem, as in many of Chaucer’s writings, there is a curious mingling of pagan and Christian elements, a strange juxtaposition of astrological notions, Greek anthropomorphism and mediaeval Christian philosophy. But pervading the whole is the idea of determinism, of the inability of the human will to struggle successfully against the destiny imposed by the powers of heaven, or against the capricious wills of the gods.
Chaucer had too keen a sense of humor, too sympathetic an outlook on life not to see the irony in the ceaseless spectacle of mankind dashing itself against the relentless wall of circumstances, fate, or what you will, in undying hope of attaining the unattainable. He saw the humor in this maelstrom of human endeavor—and he saw the tragedy too. TheKnightes Talepresents largely, I think, the humorous side of it,Troilus and Criseyde, the tragic, although there is some tragedy in theKnightes Taleand some comedy inTroilus.
It was fate that Troilus should love Criseyde, that he should win her love for a time, and that in the end heshould be deserted by her. From the very first line of the poem we know that he is doomed to sorrow:
“The double sorwe of Troilus to tellen,That was the king Priamus sone of Troye,In lovinge, how his aventures fellenFro we to wele, and after out of Ioye,My purpos is, er that I parte fro ye.”[186]
The tragedy of Troilus is also the tragedy of Criseyde, for even at the moment of forsaking Troilus for Diomede she is deeply unhappy over her unfaithfulness; but circumstance is as much to blame as her own yielding nature, for Troilus’ fate is bound up with the inexorable doom of Troy, and she could not return to him if she would.
There is no doubt that Chaucer feels the tragedy of the story as he writes. In his proem to the first book he invokes one of the furies to aid him in his task:
“Thesiphone, thou help me for tendyteThise woful vers, that wepen as I wryte!”[187]
Throughout the poem he disclaims responsibility for what he narrates, saying that he is simply following his author and that, once begun, somehow he must keep on. In the proem to the second book he says:
“Wherefore I nil have neither thank ne blameOf al this werk, but pray you mekely,Disblameth me, if any word be lame,For as myn auctor seyde, so seye I.”[188]
and concludes the proem with the words,—
“but sin I have begonne,Myn auctor shal I folwen, if I conne.”[189]
When Fortune turns her face away from Troilus, and Chaucer must tell of the loss of Criseyde his heart bleeds and his pen trembles with dread of what he must write:
“But al to litel, weylawey the whyle,Lasteth swich Ioye, y-thonked be Fortune!That semeth trewest, whan she wol bygyle,And can to foles so hir song entune,That she hem hent and blent, traytour comune;And whan a wight is from hir wheel y-throwe,Than laugheth she, and maketh him the mowe.From Troilus she gan hir brighte faceAwey to wrythe, and took of him non hede,But caste him clene oute of his lady grace,And on hir wheel she sette up Diomede;For which right now myn herte ginneth blede,And now my penne, allas! with which I wryte,Quaketh for drede of that I moot endyte.”[190]
Chaucer tells of Criseyde’s faithlessness reluctantly, reminding the reader often that so the story has it:
“And after this the story telleth us,That she him yaf the faire baye stede,The which she ones wan of Troilus;And eek a broche (and that was litel nede)That Troilus was, she yaf this Diomede.And eek, the bet from sorwe him to releve,She made him were a pencel of hir sleve.I finde eek in the stories elles-where,Whan through the body hurt was DiomedeOf Troilus, tho weep she many a tere,Whan that she saugh his wyde woundes blede;And that he took to kepen him good hede,And for to hele him of his sorwes smerte,Men seyn, I not, that she yaf him hir herte.”[191]
And in the end for very pity he tries to excuse her:
“Ne me ne list this sely womman chydeFerther than the story wol devyse,Hir name, allas! is publisshed so wyde,That for hir gilt it oughte y-now suffyse.And if I mighte excuse hir any wyse,For she so sory was for hir untrouthe,Y-wis, I wolde excuse hir yet for routhe.”[192]
We have said that Chaucer’s attitude toward the philosophical aspects of astrology is hard to determine because in most of his poems he takes an impersonal ironic point of view towards the actions he describes or the ideas he presents. His attitude toward the idea of destiny is not so hard to determine. Fortune, the executrix of the fates through the influence of the heavens rules men’s lives; they are the herdsmen, we are their flocks:
“But O, Fortune, executrice of wierdes,O influences of thise hevenes hye!Soth is, that, under god, ye ben our hierdes,Though to us bestes been the causes wrye.”[193]
Perhaps Chaucer did not mean this literally. But one is tempted to think that he, like Dante, thought of the heavenly bodies in their spheres as the ministers and instruments of a Providence that had foreseen and ordained all things.
I. Most of the terms at present used to describe the movements of the heavenly bodies were used in Chaucer’s time and occur very frequently in his writings. The significance of Chaucer’s references will then be perfectly clear, if we keep in mind that the modern astronomer’s description of theapparentmovements of the star-sphere and of the heavenly bodies individually would have been to Chaucer a description ofrealmovements.
When we look up into the sky on a clear night the stars and planets appear to be a host of bright dots on the concave surface, unimaginably distant, of a vast hollow sphere at the canter of which we seem to be. Astronomers call this expanse of the heavens with its myriad bright stars thecelestial sphereor thestar sphere, and have imagined upon its surface various systems of circles. In descriptions of the earth’s relation to the celestial sphere it is customary to disregard altogether the earth’s diameter which is comparatively infinitesimal.
If we stand on a high spot in the open country and look about us in all directions the earth seems to meet the sky in a circle which we call theterrestrial horizon. Now if we imagine a plane passing through the center of the earth and parallel to the plane in which the terrestrial horizon lies, and if we imagine this plane through the earth’s center extended outward in all directions to an infinite distance, it would cut the celestial sphere in a great circle which astronomers call thecelestial horizon. On the celestial horizon are the north, east, south and west points. The plane of the celestial horizon is, of course, different for different positions of the observer on the earth.
If we watch the sky for some time, or make several observations on the same night, we notice, by observing the changing positions of the constellations, that the stars move very slowly across the blue dome above us. The stars that rise due east of us do not, in crossing the dome of the sky, pass directly over our heads but, from the moment that we first see them, curve some distance to the south, and, after passing their highest point in the heavens, turn toward the north and set due west. A star rising due east appears to move more rapidly than one rising some distance to the north or south of the east point, because it crosses a higher point in the heavens and has, therefore, a greater distance to traverse in the same length of time. When we observe the stars in the northern sky, we discover that many of them never set but seem to be moving around an apparently fixed point at somewhat more than an angle of 40°[194]above the northern horizon and very near the north star. These are calledcircum-polar stars. The whole celestial sphere, in other words, appears to be revolving about an imaginary axis passing through this fixed point, which is called thenorth poleof the heavens, through the center of the earth and through an invisible pole (the south pole of the heavens) exactly opposite the visible one. This apparent revolution of the whole star sphere, as we know, is caused by the earth’s rotation on its axis once every twenty-four hours from west to east. Chaucer and his contemporaries believed it to be the actual revolution of the nine spheres from east to west about the earth as a center.
Fig. 1.
For determining accurately the position of stars on the celestial sphere astronomers make use of various circles which can be made clear by a few simple diagrams. In Figure 1, the observer is imagined to be at O. Then the circle NESW is the celestial horizon, which we have described above. Z, the point immediately above the observer is called thezenith, and Z′, the point immediately underneath, as indicated by a plumb line at rest, is thenadir. The line POP′ is the imaginary axis about which the star-sphere appears to revolve, and P and P′ are the poles of the heavens. The north pole P is elevated, for our latitude, at an angle of approximately 40° from the north point on the horizon. PP′ is called thepolar axisand it is evident that the earth’s axis extended infinitely would coincide with this axis of the heavens.
In measuring positions of stars with reference to the horizonastronomers use the following circles: Any great circle of the celestial sphere whose plane passes through the zenith and nadir is called avertical circle. The verticle circle SPNZ′, passing through the poles and meeting the horizon in the north and south points, N and S, is called themeridian circle, because the sun is on this circle at true mid-day. Themeridianis the plane in which this circle lies. The vertical circle, EZ′WZ, whose plane is at right angles to the meridian, is called theprime verticaland it intersects the horizon at the east and west points, E and W. These circles, and the measurements of positions of heavenly bodies which involve their use, were all employed in Chaucer’s time and are referred to in his writings.[195]
The distance of a star from the horizon, measured on a vertical circle, toward the zenith is called the star’saltitude. A star reaches its greatest altitude when on the part of the meridional circle between the south point of the horizon, S, and the north pole, P. A star seen between the north pole and the north point on the horizon, that is, on the arc PN, must obviously be acircum-polar starand would have its highest altitude when between the pole and the zenith, or on the arc PZ. When a star reaches the meridian in its course across the celestial sphere it is said toculminateor reach itsculmination. The highest altitude of any star would therefore be represented by the arc of the meridional circle between the star and the south point of the horizon. This is called the star’smeridian altitude.
Theazimuthof a star is its angular distance from the south point, measured westward on the horizon, to a vertical circle passing through the star. Theamplitudeof a star is its distance from the prime vertical, measured on the horizon, north or south.
For the other measurements used by astronomers in observations of the stars still other circles on the celestial sphere must be imagined. We know that the earth’s surface is divided into halves, called the northern and southern hemispheres, by an imaginary circle called theequator, whose plane passes through the center of the earth and is perpendicular to the earth’s axis. If the plane of the earth’s equator were infinitely extended it would describe upon the celestial sphere a great circle which would divide that sphere into two hemispheres, just as the plane of the terrestrial equator divides the earth into two hemispheres. This great circle on the celestial sphere is called thecelestial equator, or, by an older name, theequatorial, the significance of which we shall see presently. A star rising due east would traverse this great circle of the celestial sphere and set due west. The path of such a star is represented in Figure 2 by the great circle EMWM′, which also represents the celestial equator. All stars rise and set following circles whose planes are parallel to that of thecelestial equator and these circles of the celestial sphere are smaller and smaller the nearer they are to the pole, so that stars very near the pole appear to be encircling it in very small concentric circles. Stars in an area around the north celestial pole, whose limits vary with the position of the observer never set for an observer in the northern hemisphere. There is a similar group of stars around the south pole for an observer in the southern hemisphere.
Fig. 2.
The angle of elevation of the celestial equator to the horizon varies according to the position of the observer. If, for example, the observer were at the north pole of the earth, the north celestial pole would be directly above him and would therefore coincide with the zenith; this would obviously make the celestial equator and the horizon also coincide. If the observer should pass slowly from the pole to the terrestrial equator it is clear that the two circles would no longer coincide and that the angle between them would gradually widen until it reached 90°. Then the zenith would be on the celestial equator and the north and south poles of the heavens would be on the horizon.
We have still to define a great circle of the celestial sphere that is of equal importance with the celestial equator and the celestial horizon. This is the sun’s apparent yearly path, or theecliptic. We know that the earth revolves about the sun once yearly in an orbit that is not entirely round but somewhat eliptical. Now since the earth, the sun, and the earth’s orbit around the sun are always in one plane, it follows that to an observer on the earth the sun wouldappear to be moving around the earth instead of the earth around the sun. The sun’s apparent path, moreover, would be in the plane of the earth’s orbit and when projected against the celestial sphere, which is infinite in extent, would appear as a great circle of that sphere. This great circle of the celestial sphere is the ecliptic. The sun must always appear to be on this circle, not only at all times of the year but at all hours of the day; for as the sun rises and sets, the ecliptic rises and sets also, since the earth’s rotation causes an apparent daily revolution not only of the sun, moon, and planets but also of the fixed stars and so of the whole celestial sphere and of all the circles whose positions upon it do not vary. The ecliptic is inclined to the celestial equator approximately 23½°, an angle which obviously measures the inclination of the plane of the earth’s equator to the plane of its orbit, since the celestial equator and the ecliptic are great circles on the celestial sphere formed by extending the planes of the earth’s equator and its orbit to an infinite distance. Since both the celestial equator and the ecliptic are great circles of the celestial sphere each dividing it into equal parts, it is evident that these two circles must intersect at points exactly opposite each other on the celestial sphere. These points are called the vernal and the autumnal equinoxes.
We shall next define the astronomical measurements that correspond to terrestrial latitude and longitude. For some reason astronomers have not, as we might expect, applied to these measurements the terms ‘celestial longitude’ and ‘celestial latitude.’ These two terms are now practically obsolete, having been used formerly to denote angular distance north or south of the ecliptic and angular distance measured east and west along circles parallel to the ecliptic. The measurements that correspond in astronomy to terrestrial latitude and longitude are calleddeclinationandright ascensionand are obviously made with reference to the celestial equator, not the ecliptic. For taking these measurements astronomers employ circles on the celestial sphere perpendicular to the plane of the celestial equator and passing through the poles of the heavens. These are calledhour circles. The hour circle of any star is the great circle passing through it and perpendicular to the plane of the equator. The angular distance of a star from the equator measured along its hour circle, is called the star’s declination and is northern or southern according as the star is in the northern or southern of the two hemispheres into which the plane of the equator divides the celestial sphere. It is evident that declination corresponds exactly to terrestrial latitude. Right ascension, corresponding to terrestrial longitude, is the angular distance of a heavenly body from the vernal equinox measured on the celestial equator eastward to the hour circle passing through the body.
Thehour angleof a star is the angular distance measured onthe celestial equator from the meridian to the foot of the hour circle passing through the star.
Fig. 3.
It remains to describe in greater detail the apparent movements of the sun and the sun’s effect upon the seasons. In Figure 3, the great circle MWM′E represents the equinoctial and XVX′A the ecliptic. The point X represents the farthest point south that the sun reaches in its apparent journey around the earth, and this point is called thewinter solstice, because, for the northern hemisphere the sun reaches this point in mid-winter. When the sun is south of the celestial equator its apparent daily path is the same as it would be for a star so situated. Thus its daily path at the time of the winter solstice, about December 21, can be represented by the circle Xmn′. The arc gXh represents the part of the sun’s path that would be above the horizon, showing that night would last much longer than day and the rays of the sun would strike the northern hemisphere of the earth more indirectly than when the sun is north of the equator. As the sun passes along the ecliptic from X toward V, thepart of its daily path that is above the horizon gradually increases until at V, the vernal equinox, the sun’s path would, roughly speaking, coincide with the celestial equator so that half of it would be above the horizon and half below and day and night would be of equal length. This explains why the celestial equator was formerly called the equinoctial (Chaucer’s term for it). As the sun passes on toward X′ its daily arc continues to increase and the days to grow longer until at X′ it reaches its greatest declination north of the equator and we have the longest day, June 21, the summer solstice. When the sun reaches this point, its rays strike the northern hemisphere more directly than at any other time causing the hot or summer season in this hemisphere. Next the sun’s daily arc begins to decrease, day and night to become more nearly equal, at A the autumnal equinox[196]is reached and the sun again shapes its course towards the point of maximum declination south of the equator. The two points of maximum declination are calledsolstices.
The two small circles of the celestial sphere, parallel to the equator, which pass through the two points where the sun’s declination is greatest, are calledTropics; the one in the northern hemisphere is called theTropic of Cancer, that in the southern hemisphere, theTropic of Capricorn. They correspond to circles on the earth’s surface having the same names.
II. By “artificial day” Chaucer means the time during which the sun is above the horizon, the period from sunrise to sunset. The arc of the artificial day may mean the extent or duration of it, as measured on the rim of an astrolabe, or it may mean (as here), the arc extending from the point of sunrise to that of sunset. SeeAstrolabeii.7.
There has been some controversy among editors as to the correctness of the date occurring in this passage, some giving it as the 28th instead of the 18th. In discussing the accuracy of the reading “eightetethe” Skeat throws light also upon the accuracy of the rest of the passage considered from an astronomical point of view. He says (vol. 5, p. 133):
“The key to the whole matter is given by a passage in Chaucer’s ‘Astrolabe,’ pt. ii, ch. 29, where it is clear that Chaucer (who, however merely translates from Messahala) actually confuses the hour-angle with the azimuthal arc (seeAppendix I); that is, he considered it correct to find the hour of the day by notingthe point of the horizonover which the sun appears to stand, and supposing this point to advance, with auniform, not avariable, motion. The host’s method of proceeding was this. Wanting to know the hour, he observed how far the sun had moved southward along thehorizon since it rose, and saw that it had gone more than half-way from the point of sunrise to the exact southern point. Now the 18th of April in Chaucer’s time answers to the 26th of April at present. On April 26, 1874, the sun rose at 4 hr. 43 m., and set at 7 hr. 12 m., giving a day of about 14 hr. 30 m., the fourth part of which is at 8 hr. 20 m., or, with sufficient exactness, athalf past eight. This would leave a whole hour and a half to signify Chaucer’s ‘half an houre and more’, showing that further explanation is still necessary. The fact is, however, that the host reckoned, as has been said, in another way, viz. by observing the sun’s positionwith reference to the horizon. On April 18 the sun was in the 6th degree of Taurus at that date, as we again learn from Chaucer’s treatise. Set this 6th degree of Taurus on the east horizon on a globe, and it is found to be 22 degrees to the north of the east point, or 112 degrees from the south. The half of this at 56 degrees from the south; and the sun would seem to stand above this 56th degree, as may be seen even upon a globe, at about a quarter past nine; but Mr. Brae has made the calculation, and shows that it was attwenty minutes past nine. This makes Chaucer’s ‘half an houre and more’ to stand forhalf an hour and ten minutes; an extremely neat result. But this we can check again by help of the host’sotherobservation. Healsotook note, that the lengths of a shadow and its object were equal, whence the sun’s altitude must have been 45 degrees. Even a globe will shew that the sun’s altitude, when in the 6th degree of Taurus, and at 10 o’clock in the morning, is somewhere about 45 or 46 degrees. But Mr. Brae has calculated it exactly, and his result is, that the sun attained its altitude of 45 degrees attwo minutes to tenexactly. This is even a closer approximation than we might expect, and leaves no doubt about the right date being theeighteenthof April.”
Thus it appears that Chaucer’s method of determining the date was incorrect but his calculations in observing the sun’s position were quite accurate. For fuller particulars see Chaucer’sAstrolabe, ed. Skeat (E. E. T. S.) preface, p. 1.
III. It was customary in ancient times and even as late as Chaucer’s century to determine the position of the sun, moon, or planets at any time by reference to the signs of the zodiac. Thezodiacis an imaginary belt of the celestial sphere, extending 8° on each side of the ecliptic, within which the orbits of the sun, moon, and planets appear to lie. The zodiac is divided into twelve equal geometric divisions 30° in extent calledsignsto each of which a fanciful name is given. The signs were once identical with twelve constellations along the zodiac to which these fanciful names were first applied. Since the signs are purely geometric divisions and are counted from the spring equinox in the direction of the sun’s progress through them,and since through the precession of the equinoxes the whole series of signs shifts westward about one degree in seventy-two years, the signs and constellations no longer coincide. Beginning with the sign in which the vernal equinox lies the names of the zodiacal signs are Aries (Ram), Taurus (Bull), Gemini (Twins), Cancer (Crab), Leo (Lion), Virgo (Virgin), Libra (Scales), Scorpio (Scorpion), Sagittarius (Archer), Aquarius (Water-carrier), and Pisces (Fishes).
In this passage, the line “That in the Ram is four degrees up-ronne” indicates the date March 16. This can be seen by reference to Figure 1 in Skeat’s edition of Chaucer’sAstrolabe(E. E. T. S.) The astrolabe was an instrument for making observations of the heavenly bodies and calculating time from these observations. The most important part of the kind of astrolabe described by Chaucer was a rather heavy circular plate of metal from four to seven inches in diameter, which could be suspended from the thumb by a ring attached loosely enough so as to allow the instrument to assume a perpendicular position. One side of this plate was flat and was called theback, and it is this part that Figure 1 represents. The back of the astrolabe planisphere contained a series of concentric rings representing in order beginning with the outermost ring: the four quadrants of a circle each divided into ninety degrees; the signs of the zodiac divided into thirty degrees each; the days of the year, the circle being divided, for this purpose, into 365¼ equal parts; the names of the months, the number of days in each, and the small divisions which represent each day, which coincide exactly with those representing the days of the year; and lastly the saints’ days, with their Sunday-letters. The purpose of the signs of the zodiac is to show the position of the sun in the ecliptic at different times. Therefore, if we find on the figure the fourth degree of Aries and the day of the month corresponding to it, we have the date March 16 as nearly as we can determine it by observing the intricate divisions in the figure.
The next passage “Noon hyer was he, whan she redy was” means evidently, ‘he was no higher than this (i. e. four degrees) above the horizon when she was ready’; that is, it was a little past six. The method used in determining the time of day by observation of the sun’s position is explained in the Astrolabe ii, 2 and 3. First the sun’s altitude is found by means of the revolving rule at the back of the astrolabe. The rule, a piece of metal fitted with sights, is moved up and down until the rays of the sun shine directly through the sights. Then, by means of the degrees marked on the back of the astrolabe, the angle of elevation of the rule is determined, giving the altitude of the sun. The rest of the process involves the use of thefrontof the astrolabe. This side of the circular plate, shown in Fig. 2, had a thick rim with a wide depression in the middle. On therim were three concentric circles, the first showing the letters A to Z, representing the twenty-four hours of the day, and the two innermost circles giving the degrees of the four quadrants. The depressed central part of the front was marked with three circles, the ‘Tropicus Cancri’, the ‘AEquinoctialis,’ and the ‘Tropicus Capricorni’; and with the cross-lines from North to South, and from East to West. There were besides several thin plates or discs of metal of such a size as exactly to drop into the depression spoken of. The principal one of these was the ‘Rete’ and is shown in Fig. 2. “It consisted of a circular ring marked with the zodiacal signs, subdivided into degrees, with narrow branching limbs both within and without this ring, having smaller branches or tongues terminating in points, each of which denoted the exact position of some well-known star. * * * The ‘Rete’ being thus, as it were, a skeleton plate, allows the ‘Tropicus Cancri,’ etc., marked upon the body of the instrument, to be partially seen below it. * * * But it was more usual to interpose between the ‘Rete’ and the body of the instrument (called the ‘Mother’) another thin plate or disc, such as that in Fig. 5, so that portions of this latter plate could be seen beneath the skeleton-form of the ‘Rete’ (i. 17). These plates were called by Chaucer ‘tables’, and sometimes an instrument was provided with several of them, differently marked, for use in places having different latitudes. The one in Fig. 5 is suitable for the latitude of Oxford (nearly). The upper part, above the Horizon Obliquus, is marked with circles of altitude (i. 18), crossed by incomplete arcs of azimuth tending to a common centre, the zenith (i. 19).” [Skeat,Introduction to the Astrolabe, pp. lxxiv-lxxv.]
Now suppose we have taken the sun’s altitude by §2 (Pt. ii of theAstrolabe) and found it to be 25½°. “As the altitude was taken by the back of the Astrolabe, turn it over, and then let theReterevolve westward until the 1st point of Aries is just within the altitude-circle marked 25, allowing for the ½ degree by guess. This will bring the denticle near the letter C, and the first point of Aries near X, which means 9 a.m.” [Skeat’s note on theAstrolabeii. 3, pp. 189-190].
IV. Chaucer would know the altitude of the sun simply by inspection of an astrolabe, without calculation. Skeat has explained this passage in hisPreface to Chaucer’s Astrolabe(E. E. T. S.), p. lxiii, as follows:
“Besides saying that the sun was 29° high, Chaucer says that his shadow was to his height in the proportion of 11 to 6. Changing this proportion, we can make it that of 12 to 66⁄11; that is, the point of theUmbra Versa(which is reckoned by twelfth parts) is 66⁄11or 6½ nearly. (Umbra Recta and Umbra Versa were scales on the back of the astrolabe used for computing the altitudes of heavenly bodies from the height and shadows of objects. Theumbrarectawas used where the angle of elevation of an object was greater than 45°; theumbra versa, where it was less.) This can be verified by Fig. 1; for a straight edge, laid across from the 29th degree above the word ‘Occidens,’ and passing through the center, will cut the scale of Umbra Versa between the 6th and 7th points. The sun’s altitude is thus established as 29° above the western horizon, beyond all doubt.”
V.Herberwemeans ‘position.’ Chaucer says here, then, that the sun according to his declination causing his position to be low or high in the heavens, brings about the seasons for all living things. In theAstrolabe, i. 17, there is a very interesting passage explaining in detail, declination, the solstices and equinoxes, and change of seasons. Chaucer is describing the front of the astrolabe. He says: “The plate under thy rite is descryved with 3 principal cercles; of whiche the leste is cleped the cercle of Cancer, by-cause that the heved of Cancer turneth evermor consentrik up-on the same cercle. (This corresponds to the Tropic of Cancer on the celestial sphere, which marks the greatest northern declination of the sun.) In this heved of Cancer is the grettest declinacioun northward of the sonne. And ther-for is he cleped the Solsticioun of Somer; whiche declinacioun, aftur Ptholome, is 23 degrees and 50 minutes, as wel in Cancer as in Capricorne. (The greatest declination of the sun measures the obliquity of the ecliptic, which is slightly variable. In Chaucer’s time it was about 23° 31′, and in the time of Ptolemy about 23° 40′. Ptolemy assigns it too high a value.) This signe of Cancre is cleped the Tropik of Somer, oftropos, that is to seyn ‘agaynward’; for thanne by-ginneth the sonne to passe fro us-ward. (See Fig. 2 in Skeat’sPreface to the Astrolabe, vol. iii, or E. E. T. S. vol. 16.)
The middel cercle in wydnesse, of thise 3, is cleped the Cercle Equinoxial (the celestial equator of the celestial sphere); up-on whiche turneth evermo the hedes of Aries and Libra. (These are the two signs in which the ecliptic crosses the equinoctial.) And understond wel, that evermo this Cercle Equinoxial turneth iustly fro verrey est to verrey west; as I have shewed thee in the spere solide. (As the earth rotates daily from west to east, the celestial sphere appears to us to revolve about the earth once every twenty-four hours from east to west. Chaucer, of course, means here that the equinoctial actually revolves with theprimum mobileinstead of only appearing to revolve.) This same cercle is cleped also the Weyere,equator, of the day; for whan the sonne is in the hevedes of Aries and Libra, than ben the dayes and the nightes ilyke of lengthe in al the world. And ther-fore ben thise two signes called Equinoxies.
The wydeste of thise three principal cercles is cleped the Cercle of Capricorne, by-cause that the heved of Capricorne turneth evermo consentrix up-on the same cercle. (That is to say, the Tropic ofCapricorn meets the ecliptic in the sign Capricornus, or, in other words, the sun attains its greatest declination southward when in the sign Capricornus.) In the heved of this for-seide Capricorne is the grettest declinacioun southward of the sonne, and ther-for is it cleped the Solsticioun of Winter. This signe of Capricorne is also cleped the Tropik of Winter, for thanne byginneth the sonne to come agayn to us-ward.”
VI. The moon’s orbit around the earth is inclined at an angle of about 5° to the earth’s orbit around the sun. The moon, therefore, appears to an observer on the earth as if traversing a great circle of the celestial sphere just as the sun appears to do; and the moon’s real orbit projected against the celestial sphere appears as a great circle similar to the ecliptic. This great circle in which the moon appears to travel will, therefore, be inclined to the ecliptic at an angle of 5° and the moon will appear in its motion never far from the ecliptic; it will always be within the zodiac which extends eight or nine degrees on either side of the ecliptic.
The angular velocity of the moon’s motion in its projected great circle is much greater than that of the sun in the ecliptic. Both bodies appear to move in the same direction, from west to east; but the solar apparent revolution takes about a year averaging 1° daily, while the moon completes a revolution from any fixed star back to the same star in about 27¼ days, making an average daily angular motion of about 13°. The actual daily angular motion of the moon varies considerably; hence in trying to test out Chaucer’s references to lunar angular velocity it would not be correct to make use only of the average angular velocity since his references apply to specific times and therefore the variation in the moon’s angular velocity must be taken into account.
VII. On the line “In two of Taur,” etc., Skeat has the following note: “Tyrwhitt unluckily alteredtwototen, on the plea that ‘the time (four days complete, l. 1893) is not sufficient for the moon to pass from the second degree of Taurus into Cancer? And he then proceeds to shew this, taking themeandaily motion of the moon as being 13 degrees, 10 minutes, and 35 seconds. But, as Mr. Brae has shewn, in his edition of Chaucer’s Astrolabe, p. 93, footnote, it is a mistake to reckon here the moon’smeanmotion; we must rather consider heractualmotion. The question is simply, can the moon move from the 2nd degree of Taurus to the 1st of Cancer (through 59 degrees) in four days? Mr. Brae says decidedly, that examples of such motion are to be seen ‘in every almanac.’
For example, in the Nautical Almanac, in June, 1886, the moon’s longitude at noon was 30° 22′ on the 9th, and 90° 17′ on the 13th; i. e., the moon was in thefirstof Taurus on the former day, and in thefirstof Cancer on the latter day, at the same hour; which gives(very nearly) a degree more of change of longitude than we here require. The MSS all havetwoortuo, and they are quite right. The motion of the moon is so variable that the mean motion affords no safe guide.” [Skeat,Notes to the Canterbury Tales, p. 363.]
VIII. The moon’s “waxing and waning” is due to the fact that the moon is not self-luminous but receives its light from the sun and to the additional fact that it makes a complete revolution around the earth with reference to the sun in 29½ days. When the earth is on the side of the moon that faces the sun we see the full moon, that is, the whole illuminated hemisphere. But when we are on the side of the moon that is turned away from the sun we face its unilluminated hemisphere and we say that we have a ‘new moon.’ Once in every 29½ days the earth is in each of these positions with reference to the moon and, of course, in the interval of time between these two phases we are so placed as to see larger or smaller parts of the illuminating hemisphere of the moon, giving rise to the other visible phases.
When the moon is between the earth and the sun she is said to be inconjunction, and is invisible to us for a few nights. This is the phase callednew moon. As she emerges from conjunction we see the moon as a delicate crescent in the west just after sunset and she soon sets below the horizon. Half of the moon’s surface is illuminated, but we can see only a slender edge with the horns turned away from the sun. The crescent appears a little wider each night, and, as the moon recedes 13° further from the sun each night, she sets correspondingly later, until in her first quarter half of the illuminated hemisphere is turned toward us. As the moon continues her progress around the earth she gradually becomes gibbous and finally reaches a point in the heavens directly opposite the sun when she is said to be inopposition, her whole illumined hemisphere faces us and we havefull moon. She then rises in the east as the sun sets in the west and is on the meridian at midnight. As the moon passes from opposition, the portion of her illuminated hemisphere visible to us gradually decreases, she rises nearly an hour later each evening and in the morning is seen high in the western sky after sunrise. At herthird quartershe again presents half of her illuminated surface to us and continues to decrease until we see her in crescent form again. But now her position with reference to the sun is exactly the reverse of her position as a waxing crescent, so that her horns are now turned toward the west away from the sun, and she appears in the eastern sky just before sunrise. The moon again comes into conjunction and is lost in the sun’s rays and from this point the whole process is repeated.
IX. That the apparent motions of the sun and moon are not so complicated as those of the planets will be clear at once if we rememberthat the sun’s apparent motion is caused by our seeing the sun projected against the celestial sphere in the ecliptic, the path cut out by the plane of the earth’s orbit, while in the case of the moon, what we see is the moon’s actual motion around the earth projected against the celestial sphere in the great circle traced by the moon’s own orbital plane produced to an indefinite extent. These motions are further complicated by the rotation of the earth on its own axis, causing the rising and setting of the sun and the moon. These two bodies, however, always appear to be moving directly on in their courses, each completing a revolution around the earth in a definite time, the sun in a year, the moon in 29½ days. What we see in the case of the planets, on the other hand, is a complex motion compounded of the effects of the earth’s daily rotation, its yearly revolution around the sun, and the planets’ own revolutions in different periods of time in elliptical orbits around the sun. These complex planetary motions are characterized by the peculiar oscillations known as ‘direct’ and ‘retrograde’ movements.