Today | News | Books | Recipes Adventure | Science Fiction | Ghost stories | Poetry | Children | History Bookcan tell, from two observations of a planet properly made, whether the planet's movement is direct or retrograde (ii. 35). The disc shewn in Fig. 14 helps to shew the 'equations of houses' (ii. 36). The four cardinal points can be found _without_ an astrolabe, by an experiment properly conducted (ii. 38). The astrolabe can be used to find the degree of the zodiac with which any planet ascends, even when the planet is not situated in the ecliptic (ii. 40). By the use of the _Umbra Recta_ on the back of the instrument, we can take the altitude of an accessible object by a single observation (ii. 41); or of an inaccessible object by two observations (ii. 43). Or, the height of an inaccessible object may likewise be taken by two observations, by the scale marked _Umbra Versa_ (ii. 42). The few Conclusions not here referred to are chiefly explanatory, or of minor interest. § 30. STARS MARKED ON THE RETE. Several of the Latin MSS. upon the Astrolabe give a list of the stars marked upon the Rete. There is a double list, for example, in MS. Ii. 3. 3, in the Cambridge University Library, fol. 70, back. It is given in the form of two tables; the first mentions forty-nine stars, with the degrees of the zodiac which south along with them, and their declinations from the equinoctial line. The second table mentions some only of _the same_ stars, with their longitudes and latitudes, as referred to the ecliptic. A list of the principal stars usually marked upon the Rete, as shewn in Fig. 2, is given in the Note to Part i. § 21. 4 (p. 357). Fig. 9 shews another Rete, with many of the same stars, with the addition of Markep ([iota] Argous). Alchimech is the same as Azimech, i.e. [alpha] Virginis; Cor Leonis is [alpha] Leonis; and Alfart is [alpha] Hydræ. § 31. ASTROLOGICAL NOTES. For a general sketch of Astrology, see the English Cyclopaedia, s.v. Worthless as the science is, it is useful to have a few 'facts' for handy reference. I therefore attempt a synopsis of the chief points of it, drawn from Johannis Hispalensis Isagoge in Astrologiam. To save space, I give the information in a tabular form, wherein I denote the twelve Signs by A., T., G., C., L., V., Li., S., Sa., Cp., Aq., P.; and the seven Planets, Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon, by St., J., Ms., Sn., V., My., Mo. What the table exactly means shall be explained presently. Signs.| Man. | Ex. | Day. | Nt. | Com. |Face 1.|Face 2.|Face 3. ------+------+----------+------+------+------+-------+-------+------- A. | Ms. | Sn. (19) | Sn. | J. | St. | Ms. | Sn. | V. T. | V. | Mn. (3) | V. | Mn. | Ms. | My. | Mn. | St. G. | My. | D. H. | St. | My. | J. | J. | Ms. | Sn. C. | Mn. | J. (15) | V. | Ms. | Mn. | V. | My. | Mn. L. | Sn. | | Sn. | J. | St. | St. | J. | Ms. V. | My. | My. (15) | V. | Mn. | Ms. | Sa. | V. | My. Li. | V. | St. (19) | St. | My. | J. | Mn. | St. | J. S. | Ms. | | V. | Ms. | Mn. | Ms. | Sn. | V. Sa. | J. | D. T. | Sn. | J. | St. | My. | Mn. | St. Cp. | St. | Ms. (28) | V. | Mn. | Ms. | J. | Ms. | Sn. Aq. | St. | | St. | My. | J. | V. | My. | Mn. P. | J. | V. (21) | V. | Ms. | Mn. | St. | J. | Ms. The first line is to be read thus. Aries is the mansion (or house) of Mars; the exaltation (or honour) of the Sun, in the 19th degree of the sign; the lord of the Triplicity of Aries with its attendant signs is the Sun by day, Jupiter by night, and Saturn in Common, both by day and night; the first Face of Aries (degrees 1 to 10) is that of Mars; the second Face (degrees 11 to 20) is that of the Sun; the third Face (degrees 21 to 30) is that of Venus. And so on for the rest; noting that Gemini is the Exaltation of the Dragon's Head (D. H.), and Sagittarius that of the Dragon's Tail (D. T.). The meanings of the words are as follows:-- A _Mansion_ or _House_ appears to be that sign in which the planet is peculiarly at home for some reason or other. The _Exaltation_ or _Honour_ is that degree of a sign in which the planet named has its greatest power; but the degree was often neglected, and Aries was called the Exaltation of the Sun, simply. The _Fall_ (Lat. _occasus vel detrimentum_) of a planet is the sign opposite its mansion. Libra is opposite Aries; therefore Libra is the Fall of Mars. The _Dejection_ or _Depression_ (Lat. _dedecus_) of a planet is the sign opposite to that of its exaltation. Libra is opposite Aries; therefore Libra is the Dejection of the Sun. And so on. A _Triplicity_ is a combination of three signs in the form of a triangle, each 120° apart. Thus Aries, Leo, and Sagittarius form the first triplicity; Taurus, Virgo, Capricorn, the second; Gemini, Libra, Aquarius, the third; Cancer, Scorpio, Pisces, the fourth. Equal divisions of a sign (third-parts, namely) are called _Faces_. There were also unequal divisions called _Terms_. The 'mobill' or movable signs are Aries, Cancer, Libra, Capricorn. The 'fixe' or fixed signs are Taurus, Leo, Scorpio, Aquarius. The 'common' signs are Gemini, Virgo, Sagittarius, Pisces. The signs Aries, Gemini, Leo, &c. (taking _every other_ sign) are _diurnal_ or _masculine_. The rest, Taurus, Cancer, &c., are _nocturnal_ or _feminine_. The first six signs, Aries to Virgo, are _northern_ or _sinister_ signs. So called because astrologers looked towards the east or ascendent. The last six, Libra to Pisces, are _southern_ or _dexter_ signs. The signs Cancer to Sagittarius are _western_, _sovereign_, _right_, or _direct_ signs. Cf. Astrol. ii. 28, and see Fig. 2. The rest, Capricorn to Gemini, are _eastern_, _obedient_, _tortuous_, or _oblique_ signs. This is all that a reader is likely to want. For other points, see the authorities. DESCRIPTION OF THE PLATES. § 32. Plate I. Fig. 1. The flat back of the Astrolabe; see § 28. Plate II. Fig. 2. The front of the Astrolabe, with raised border. In the wide depression in the middle, the plate called the 'Rete' is dropped in, and is shewn in its primary position. Other positions of it are sketched in Fig. 11 and Fig. 12. Plate III. Fig. 3. The 'Rewle' carrying two sights, which revolved at the back of the Astrolabe. Astrol. i. 13. Fig. 4. The central 'Pin,' shewn with the 'Wedge' inserted through it. Astrol. i. 14; cf. Fig. 7. Fig. 5. One of the Tables or discs, used by being dropped within the depression on the _front_ of the Astrolabe; i. 17. They were marked differently, according to the latitude of the place. The one here drawn is suitable for the latitude of Oxford, nearly. Fig. 6. The 'Label,' which revolved at the _front_ of the Astrolabe; i. 22. Plate IV. Fig. 7. Another form of the 'Pin,' shewing the Wedge cut into the shape of a Horse (i. 14); from MS. Camb. Ii. 3. 3. Fig. 8. Diagram, shewing how to draw the three 'principal circles'; see footnote on p. 183. Fig. 9. Another form of the 'Rete,' from MS. Ii. 3. 3; cf. Fig. 2. This figure shews the 'Almury' very clearly; Astrol. i. 23. Plate V. Fig. 10. Diagram of the nine spheres; from MS. Camb. Ii. 3. 3. Astrol |