Imatges de pàgina
PDF
EPUB

in what place of be firmament ; And also her arising in thy orizonte, and how longe þat thei wol ben aboue be erthe wiþ þe Arke of þe nyght / And loke euermore hov many degrees pou fynde eny sterre at þat tyme sitting vpon pin Almycanteras, and vp-on as many degrees sette pou pe reule vpon pe altitude in þe bordere; And by the mediacioun of þy eye through þe .2. smale holes shalt thou se pe same sterre by the same altitude aforseid, And so by this conclusioun may pou redely knowe whiche is oo sterre from a-noper in the firmament / for as many as ben in the Astrelabie. For by pat same altitude shal thou se that same sterre, & non othir / for pere ne wolle non othir altitude accorde perto.'

30. Alhabor ; i. e. Sirius or the Dog-star, as is evident from the fact of its being represented by a dog's head on the Astrolabe ; see also the table of stars marked on the Astrolabe (in MS. Camb. Univ. Lib. li. 3. 3, fol. 70, back), which gives the declination 15° S, the latitude 39° S, and places the star in Cancer. It is also plainly described in the same table as being in ore canis,' so that it is difficult to resist the conclusion of the identity of Alhabor and Sirius. Mr. Brae, following later copies that have different readings of the numbers employed, identifies Alhabor with Rigel or B Orionis. This is impossible, from the fact that Rigel and Alhabor both occur in the diagrams and tables ; see, for instance, Fig. 2. It is true that Rigel was sometimes called Algebar, but Alhabor stands rather for the Arabic Al-'abür. The Arabic name for the constellation Canis Major was Al-kalb al-akbar, “greater dog,' as distinguished from Al-kalb al-asghar, or 'lesser dog’; and the star a Canis Majoris was called Al-shira al-'abür, the former of which terms represented the Greek geipios (Sirius), whilst from the latter (al-'abür) we have our Alhabor. See Ideler, Über den Ursprung und die Bedeutung der Sternnamen, pp. 237, 256.

§ 4. “The houses (in astrology) have different powers. The strongest of all these is the first, which contains the part of the heaven about to rise : this is called the ascendant; and the point of the ecliptic which is just rising is called the horoscope.'-English Encyclopædia; art. Astrology.

21. In the English Cyclopædia, art. Astrology, a quotation is given from an astrological work, in reply to the question whether the 'querent' should succeed as a cattle-dealer. It contains some words very similar to Chaucer's. 'If the lord of the sixth be in quartile, or in opposition to the dispositor of the part of Fortune, or the Moon, the querent cannot thrive by dealing in small cattle. The same if the lord of the sixth be afflicted either by Saturn, Mars, or the Dragon's Tail; or be found either retrograde, combust, cadent, or peregrine. (See l. 33.] The Dragon's Tail and Mars shew much loss therein by knaves and thieves, and ill bargains, &c.; and Saturn denotes much damage by the rot or murrain.' The evil influence of the Dragon's Tail is treated of in the last chapter of 'Hermetis Philosophi de revolutionibus nativitatum,' fol. Basileæ ; n. d.

32. 'May seen the ascendant. Cf. 'Cum dominator ascendens viderit, res quæ occulta est secundum ascendentis naturam erit; quod si non videt, illud erit secundum naturam loci in quo ipse est dominator'; Cl. Ptolemæi Centiloquium ; sect. 90.

33. combust, said of a planet when its light is quenched by being too near the sun. Tyrwhitt, in his Glossary, says that it is used when the planet is not more than 81 degrees distant from the sun. Cf. Troilus, iii. 717, and the note.

40. Face. See note to Part I. sect. 21. 1. 50 (p. 359). The late copies are very incorrect hereabouts.

§ 6. 9. Mr. Brae well calls attention here to the absurd errors in the printed copies. Thynne has in the 320 signe,' and Speght 'in the xxiii signe. The signs of the zodiac are only twelve, and the one opposite to the ist is the 7th.

§ 8. I see no reason for supposing this proposition to be an interpolation, as Mr. Brae suggests. Though similar to § 11, it is not identical with it. Moreover, it occurs in Messahala.

§ 9. 2. the chapitre beforn, i.e. a previous chapter, viz. in sect. 6. The expression supplies no argument for altering the order of the conclusions.

4. same manere, i.e. a like manner. The 'vulgar night' clearly means that the quantity of the 'crepuscules' must be subtracted from the arch of the night.'

§ 13. 5. cours, course ; heyest cours, highest point of the path. Late copies have lyne ; for which Mr. Brae suggested degre.

§ 14. 6. but 2 degrees. Suppose the sun's midday altitude is 49°, in latitude 52°. Then the co-latitude is 38°, and the sun's declination 1° North. This corresponds nearly (roughly speaking) to the ist degrees of Taurus and Virgo. Which is right can 'lightly' be known by the time of year, for the sun cannot be in Virgo if the month be April. Compare sect. 15.

§ 17. This conclusion, as pointed out in the footnote, is not correct in theory, but can be made nearly so in practice, by taking the two altitudes very near the meridian. This is directly implied in the words' passeth any-thing the sowth westward,' i. e. passes ever so little westward of the south line; cf. note below to 38. 10. Consequently, the first observation must also be taken very near the meridian.

25. site, situation. Late copies, sight. This proves that the word site is Chaucerian, and clears up the reading in Ho. Fame, 1114.

§ 18. Instead of reckoning a star's right ascension by referring it to the equator, it was reckoned by observing the degree of the zodiac which southed along with it. This is expressed in the first 'Table of fixed stars' in MS. Camb. Univ. Lib. Ii. 3. 3 (fol. 70, back) by the phrase 'cum gradibus, quibus celum mediant'; the other co-ordinate of position was the star's declination from the equator, as in the modern method. The ancients also used the co-ordinates of longitude and latitude of a star, the longitude being reckoned along the ecliptic, and

[ocr errors]

the latitude along great circles through the poles of the ecliptic; as appears from the second Table in the same MS.

$ 19. 6. equinoxial. This, as explained in the footnote, should be 'ecliptik'; but I can find no MS. authority for the alteration, though the correction is practically made in l. 13.

§ 22. 13. place. Late copies and old editions, planet; absurdly. Latitudes of several places are given in old Latin MSS. They are frequently incorrect.

§ 23. 3. The star A is shewn by the numbers to be the Pole-star, and is obviously the one to be observed in order to find the altitude of the Pole. What the star F is, is of no consequence. The numbers used in other copies are different, and much less satisfactory. That the star A is the Pole-star or some star near the pole in this conclusion' is rendered probable also by the wording of the next 'conclusion'; which extends the working of it to the case of any other star, provided it be a star that never sets.

$ 25. 19. When Chaucer says that the latitude of Oxford is certain minutes less,' he probably means no more than that the latitude of Oxford was 51 degrees and 50 minutes, as in the text. For I suspect the original reading of the passage made the sun's altitude 38 degrees only, and the latitude 52 degrees; indeed, the passage stands so in MSS. C and P, both good authorities. But he added the statement that the latitude of Oxford was less than 52 degrees. It is probable that, on second thoughts, he put in the number of minutes, and forgot to strike out the clause " I sey nat this,' &c., which was no longer necessary. Minutes were seldom reckoned otherwise than by tens ; 'a few minutes less than 50' (say 47) is a refinement to which the ancients seldom attained. Hence the amount of 10 minutes is vaguely spoken of in l. 31 as 'odde Minutes.' Minutes were clearly not much considered. In the present case, we are assisted by Chaucer's express statement in sect. 22. 1. 6. The true latitude of Oxford is between 51° 45' and 51° 46'.

§ 26. 8-11. It is singular that this sentence, obviously wanted, should appear only in one MS., and has, accordingly, been omitted in all previous editions. There can be no doubt about the genuineness of it, as it so exactly gives the right sense, and happily supplies the words right orisonte' in l. 11; thus enabling the author to say, as in l. 21 he does say—this forseid righte orisonte.'

16. this figure. Here occurs, in some of the MSS., a diagram representing a circle, i.e. a disc of the astrolabe, with straight lines drawn across it from left to right.

17. assensiouns in the righte cercle. This exactly answers to our modern right ascension.' We hence obtain the true origin of the phrase. Right ascension’ was, originally, the ascension of stars at places situate on the equator, and was most conveniently measured along the equatorial circle, by observation of the times of transit of the various stars across the meridian. In other latitudes, the ascension of

every degree of the zodiac could be easily tabulated by observing what degree of the equator came to the meridian with the said degree of the zodiac ; see l. 20. It hence appears that, whilst persisting in using "longitudes’and reckoning along the zodiac, the ancients were obliged, in practice, to refer the degrees of longitude to the equator. The modern method of recognizing this necessity, and registering right ascensions as of more importance than longitudes, is a great improvement. The ancients were restrained from it by their unnecessary reverence for the zodiac. Cf. Ptolemy's Almagest, lib. i. xiji.

§ 29. Chaucer omits to say that the experiment should be made when the sun is very nearly on the meridian. Otherwise, the confusion of the azimuth with the hour-angle might cause a considerable

[ocr errors]

error.

§ 30. 3. That the phrase 'wey of the sonne' really means the sun's apparent diurnal course in this conclusion, may be further seen by consulting the Latin of Messahala. Cf. the Critical Note on p. 236.

§ 31. In my footnote, I have used the expression ‘it does not mean, as it should, the zenith point.' I mean—'as, according to our modern ideas, it should ';—for the derivation of zenith shews that the meaning used in this proposition is the older meaning of the two. See note above to i. 19. 7 (p. 357).

6. 24 parties. These 24 parts were suggested by the 24 hours of the day. The '32 parts' used by shipmen’are due to the continual halving of angles. Thus, the four cardinal points have points half-way between them, making eight points; between which, we can insert eight more, making sixteen ; and between these, sixteen more, making thirtytwo. Hence the 32 points of the compass.

$ 33. 5. We should probably insert or south after the word north. Sach an insertion is authorised by MSS. B. and C.

§ 34. 3. That 'upon the mones syde' means nearly in the same azimuth as the moon, is apparent from l. 11 below, where Chaucer says that some treatises make no exception even if the star is not quite in the same azimuth. This was certainly a rough mode of observation.

§ 35. 9. right side, East side. See i. 6. 1 (p. 179).

18. episicle, epicycle. To account for the planetary motions, epicycles were invented. The moon, for instance, was supposed to revolve round a moving centre, which centre itself moved round the earth in a perfect circle. This came a little nearer to the true motion in some instances, but was hopelessly wrong, and nothing could be made of it, even when a second epicycle, revolving about a centre which moved in the first epicycle, was superadded. All that Chaucer says here is, that, whilst the centre of the moon's epicycle had a direct motion, the moon's motion in the epicycle itself was a reverse one, unlike that of the other planetary bodies. The subject is hardly worth further discussion, so I merely refer the reader to the Almagest, lib. iv. c. 5; and lib. ix. C. 5.

§ 36. The 'equations of houses ' means the dividing of the sphere into equal portions, and the right numbering of those portions or houses. The most important house was the first, or ascendent, just rising; the next in importance was the tenth, which was just coming on the meridian; then come the seventh or descendent, just about to set, and the fourth, just coming to the line of midnight. The next in importance were the succedents, or houses immediately following these, viz. the second, the eleventh, the eighth, and the fifth. The least important were the third, twelfth, ninth, and sixth. See Fig. 14.

§ 37. 18. thise 3 howsez. That is, the nadirs of the 2nd, 3rd, and 4th houses give the houses that follow,' i.e. the 8th, 9th, and ioth. The word 'follow'here seems to refer, not to position, but to the order in which the houses may most conveniently be found. Chaucer omits to add that the beginnings of the 5th and 6th houses can be found in a similar way, because it is sufficiently evident. It is all from Messahala.

§ 38. 1. for warping, the brodere the bettre. This may mean, either (1) to prevent warping, the thicker the better; or (2) to prevent the errors arising from warping (for fear of warping), the larger the better. I believe the latter to be the true interpretation ; for it is better thus to guard against possible errors than to make the plate very thick and, at the same time, small. Besides which, the usual meaning of brodere is wider, larger, more ample. Indeed, we find the very expression 'non sit tamen nimis parvus' in the 4th section of the Practica Chilindri of John Hoveden, published by the Chaucer Society; which see.

8. fro the centre, i. e. sticking up above the centre, the length of the wire being equal to a fourth of the diameter, or half the radius, of the circle. This proportion would do for many days in the year; but in the summer time, the pin would bear to be rather longer. Still, we need not alter the text. Cf. the Critical Note on p. 237.

10. any-thing, i. e. ever so little ; so ony-thyng in l. 13; cf. § 17. 6.

§ 39. Though MS. A is rather corrupt here, there is little doubt about the corrections to be made. See the Critical Notes, p. 237.

19. That is, the latitude, or breadth, of a climate, or belt, is measured along a line which goes from North to South as far as the earth extends; so that the latitude of the first climate, for example, is measured from the beginning of it to the end of the same, in a due northerly direction. Other authors, he explains, reckoned the latitude of a climate always from the equinoxial line, instead of from the parallel of latitude which terminated the climate immediately to the south of it. Thus the latitude of the fourth climate might mean, either the breadth of that belt itself, or the whole breadth from the equator to the Northern limit of that climate. The MS. E. 2 in St. John's College, Cambridge, contains (besides Chaucer's 'Astrolabe') a Latin treatise entitled ' De septem climatibus expositio.' We find mention of the climates' also in MS. Camb. li. 3. 3, fol. 33 b, where a diagram appears representing

« AnteriorContinua »