PART I.

Here biginneth the descripcion of the Astrolabie.

[1.] Thyn Astrolabie hath a ring to putten on the thoumbe of

thy right hand in taking the heighte of thinges. And tak keep, for

from hennes-forthward, I wol clepe the heighte of any thing that

is taken by thy rewle, the altitude, with-oute mo wordes.

[2.] This ring renneth in a maner turet, fast to the moder of

thyn Astrolabie, in so rowm a space that hit desturbeth nat the

instrument to hangen after his righte centre.

[3.] The Moder of thyn Astrolabie is the thikkeste plate, perced

with a large hole, that resseyveth in hir wombe the thinne plates

compowned for diverse clymatz, and thy riet shapen in manere

of a net or of a webbe of a loppe; and for the more declaracioun,

lo here the figure.

[4.] This moder is devyded on the bak-half with a lyne, that

cometh dessendinge fro the ring down to the nethereste bordure.

The whiche lyne, fro the for-seide ring un-to the centre of the

large hole amidde, is cleped the south lyne, or elles the lyne

meridional. And the remenant of this lyne downe to the bordure

is cleped the north lyne, or elles the lyne of midnight. And for

the more declaracioun, lo here the figure.

[5.] Over-thwart this for-seide longe lyne, ther crosseth him

another lyne of the same lengthe from est to west. Of the

whiche lyne, from a litel croys + in the bordure un-to the centre

of the large hole, is cleped the Est lyne, or elles the lyne Orientale;

and [the remenant] of this lyne fro the forseide + un-to the bordure,

is cleped the West lyne, or the lyne Occidentale. Now hastow

here the foure quarters of thin Astrolabie, devyded after the foure

[principals] plages or quarters of the firmament. And for the more

declaracioun, lo here thy figure.

[6.] The est side of thyn Astrolabie is cleped the right side, and

the west side is cleped the left side. Forget nat this, litel Lowis.

Put the ring of thyn Astrolabie upon the thoumbe of thy right

hand, and thanne wole his right syde be toward thy left syde, and

his left syde wol be toward thy right syde; tak this rewle general,

as wel on the bak as on the wombe-side. Upon the ende of this

est lyne, as I first seide, is marked a litel +, wher-as evere-mo

generaly is considered the entring of the first degree in which the

sonne aryseth. And for the more declaracioun, lo here the

figure.

[7.] Fro this litel + up to the ende of the lyne meridional, under

the ring, shaltow finden the bordure devyded with 90 degrees;

and by that same proporcioun is every quarter of thin Astrolabie

devyded. Over the whiche degrees ther ben [noumbres of augrim],

that devyden thilke same degrees fro fyve to fyve, as sheweth by

longe strykes by-twene. Of whiche longe strykes the space by-twene

contienith a mile-wey. And every degree of the bordure

contieneth foure minutes, that is to seyn, minutes of an houre.

And for more declaracioun, lo here the figure.

[8.] Under the compas of thilke degrees ben writen the names of

the Twelve Signes, as Aries, Taurus, Gemini, Cancer, Leo, Virgo,

Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces; and

the nombres of the degrees of tho signes ben writen in augrim

above, and with longe devisiouns, fro fyve to fyve; devyded fro

tyme that the signe entreth un-to the laste ende. But understond

wel, that thise degrees of signes ben everich of hem considered

of 60 minutes, and every minute of 60 secondes, and so

forth in-to smale fraccions infinit, as seith [Alkabucius]. And

ther-for, know wel, that a degree of the bordure contieneth foure

minutes, and a degree of a signe contieneth 60 minutes, and

have this in minde. And for the more declaracioun, lo here

thy figure.

[9.] Next this folweth the Cercle of the Dayes, that ben figured

in maner of degrees, that contienen in noumbre 365; divyded

also with longe strykes fro fyve to fyve, and the nombres in

augrim writen under that cercle. And for more declaracioun, lo

here thy figure.

[10.] Next the Cercle of the Dayes, folweth the Cercle of the

names of the Monthes; that is to seyen, Ianuare, Februare,

Marcius, Aprile, Mayus, Iuin, Iulius, Augustus, Septembre,

October, Novembre, Decembre. The names of thise monthes

were cleped [in Arabiens], somme for hir propretees, and some by

statutz of lordes, some by other lordes of Rome. Eek of thise

monthes, as lyked to Iulius Cesar and to Cesar Augustus, some

were compowned of diverse nombres of dayes, as Iuil and

August. Thanne hath Ianuare 31 dayes, Februare 28, March

31, Aprille 30, May 31, Iunius 30, Iulius 31, Augustus 31,

September 30, Octobre 31, Novembre 30, December 31.

Natheles, al-though that Iulius Cesar took 2 dayes out of Feverer

and put hem in his moneth of Iuille, and Augustus Cesar cleped

the moneth of August after his name, and ordeyned it of 31 dayes,

yit truste wel, that the sonne dwelleth ther-for nevere the more ne

lesse in oon signe than in another.

[11.] Than folwen the names of the Halidayes in the Kalender,

and next hem the lettres of the Abc. on which they fallen. And

for the more declaracioun, lo here thy figure.

[12.] Next the forseide Cercle of the Abc., under the cros-lyne,

is marked the scale, in maner of two squyres, or elles in manere

of laddres, that serveth by hise 12 poyntes and his devisiouns of

ful many a subtil conclusioun. Of this forseide scale, fro the

croos-lyne un-to the verre angle, is cleped umbra versa, and the

nether partie is cleped the umbra recta, or elles umbra extensa.

And for the more declaracioun, lo here the figure.

[13.] Thanne hastow a brood Rewle, that hath on either ende a

square plate perced with a certein holes, some more and some

lesse, to resseyven the stremes of the sonne by day, and eek

by mediacioun of thyn eye, to knowe the altitude of sterres by

nighte. And for the more declaracioun, lo here thy figure.

[14.] Thanne is ther a large Pyn, in maner of an extree, that

goth thorow the hole that halt the tables of the clymates and the

riet in the wombe of the Moder, thorw which Pyn ther goth a

litel wegge which that is cleped 'the hors,' that streyneth alle

thise parties to-hepe; this forseide grete Pyn, in maner of an

extree, is imagined to be the Pol Artik in thyn Astrolabie.

And for the more declaracioun, lo here the figure.

[15.] The wombe-side of thyn Astrolabie is also devyded with a

longe croys in foure quarters from est to west, fro south to north,

fro right syde to left syde, as is the bak-syde. And for the more

declaracioun, lo here thy figure.

[16.] The bordure of which wombe-side is devyded fro the poynt

of the est lyne un-to the poynt of the south lyne under the ring,

in 90 degres; and by that same proporcioun is every quarter

devyded as is the bak-syde, that amonteth 360 degrees. And

understond wel, that degrees of this bordure ben answering and

consentrik to the degrees of the Equinoxial, that is devyded in

the same nombre as every othere cercle is in the heye hevene.

This same bordure is devyded also with 23 lettres capitals and a

smal croys + above the south lyne, that sheweth the 24 houres

equals of the clokke; and, as I have said, 5 of thise degrees

maken a mile-wey, and 3 mile-wey maken an houre. And every

degree of this bordure conteneth 4 minutes, and [every minut] 60

secoundes; now have I told thee twye. And for the more

declaracioun, lo here the figure.

[17.] The plate under thy riet is descryved with 3 principal

cercles; of which the leste is cleped the cercle of Cancer, by-cause

that the heved of Cancer turneth evermor consentrik up-on

the same cercle. 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. This

signe of Cancre is cleped the Tropik of Somer, of [tropos], that is

to seyn 'agaynward'; for thanne by-ginneth the sonne to passe

fro us-ward. And for the more declaracioun, lo here the figure.

The middel cercle in wydnesse, of thise 3, is cleped the Cercle

Equinoxial; up-on whiche turneth evermo the hedes of Aries and

Libra. 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]. 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 the Equinoxies. And alle that moeveth with-in the

hevedes of thise Aries and Libra, his moeving is cleped northward;

and alle that moeveth with-oute thise hevedes, his moeving

is cleped south-ward as fro the equinoxial. Tak keep of thise

latitudes north and sowth, and forget it nat. By this Cercle

Equinoxial ben considered the 24 houres of the clokke; for

everemo the arysing of 15 degrees of the equinoxial maketh an

houre equal of the clokke. This equinoxial is cleped the girdel

of the firste moeving, or elles of the [angulus] primi motus vel

primi mobilis. [And nota], that firste moeving is cleped 'moeving'

of the firste moevable of the 8 spere, whiche moeving is fro est to

west, and eft agayn in-to est; also it is clepid 'girdel' of the first

moeving, for it departeth the firste moevable, that is to seyn, the

spere, in two ilyke parties, evene-distantz fro the poles of this

world.

The wydeste of thise three principal cercles is cleped the

Cercle of Capricorne, by-cause that the heved of Capricorne

turneth evermo consentrik up-on the same cercle. 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. And for

the more declaracioun, lo here thy figure.

[18.] Upon this forseide plate ben compassed certein cercles

that highten Almicanteras, of which som of hem semen perfit

cercles, and somme semen inperfit. The centre that standith

a-middes the narwest cercle is cleped the Senith; and the

netherest cercle, or the firste cercle, is clepid the Orisonte, that

is to seyn, the cercle that devydeth the two emisperies, that is,

the partie of the hevene a-bove the erthe and the partie be-nethe.

Thise Almicanteras ben [compowned by two and two], al-be-it so

that on divers Astrolabies some Almicanteras ben devyded by oon,

and some by two, and somme by three, after the quantite of the

Astrolabie. This forseide senith is imagened to ben the verrey

point over the crowne of thyn heved; and also this senith is the

verrey pool of the orisonte in every regioun. And for the

more declaracioun, lo here thy figure.

[19.] From this senith, as it semeth, ther come a maner crokede

strykes lyke to the clawes of a loppe, or elles like to the werk of a

womanes calle, in kerving overthwart the Almikanteras. And

thise same strykes or divisiouns ben cleped Azimuthz. And they

devyden the orisonte of thyn Astrolabie in four and twenty

devisiouns. And thise Azimutz serven to knowe the costes of the

firmament, and to othre conclusiouns, as for to knowe the [cenith]

of the sonne and of every sterre. And for more declaracioun, lo

here thy figure.

[20.] Next thise azimutz, under the Cercle of Cancer, ben ther

twelve devisiouns embelif, moche like to the shap of the azimutes,

that shewen the spaces of the houres of planetes; and for more

declaracioun, lo here thy figure.

[21.] The Riet of thyn Astrolabie with thy zodiak, shapen in

maner of a net or of a loppe-webbe after the olde descripcioun,

which thow mayst tornen up and doun as thy-self lyketh, conteneth

certein nombre of [sterres fixes], with hir longitudes and latitudes

determinat; yif so be that the makere have nat erred. The names

of the sterres ben writen in the margin of the riet ther as they sitte;

of whiche sterres [the smale poynt is cleped the Centre]. And

understond also that alle sterres sittinge with-in the zodiak of thyn

Astrolabie ben cleped '[sterres of the north],' for they arysen by

northe the est lyne. And alle the remenant fixed, out of the

zodiak, ben cleped 'sterres of the south;' but I sey nat that they

arysen alle by southe the est lyne; witnesse on [Aldeberan] and

Algomeysa. Generally understond this rewle, that thilke sterres

that ben cleped sterres of the north arysen rather than the degree

of hir longitude, and alle the sterres of the south arysen after the

degree of hir longitude; this is to seyn, sterres fixed in thyn

Astrolabie. The mesure of this longitude of sterres is taken in the

lyne ecliptik of hevene, under which lyne, whan that the sonne

and the mone ben lyne-right or elles in the superfice of this lyne,

than is the eclips of the sonne or of the mone; as I shal declare,

and eek the cause why. But sothly the Ecliptik Lyne of thy

zodiak is the outtereste bordure of thy zodiak, ther the degrees ben

marked.

Thy Zodiak of thyn Astrolabie is shapen as a compas which that

conteneth a large brede, as after the quantite of thyn Astrolabie;

in ensample that the zodiak in hevene is imagened to ben a superfice

contening a latitude of twelve degrees, wheras al the remenant

of cercles in the hevene ben imagined verrey lynes with-oute eny

latitude. [Amiddes] this celestial zodiak ys imagined a lyne, which

that is cleped the Ecliptik Lyne, under which lyne is evermo the

wey of the sonne. Thus ben ther six degrees of the zodiak on

that on side of the lyne, and six degrees on that other. This

zodiak is devided in twelve principal devisiouns, that departen the

twelve signes. And, for the [streitnes] of thin Astrolabie, than is

every smal devisioun in a signe departid by two degrees and two;

I mene degrees contening sixty minutes. And this forseide

hevenissh zodiak is cleped the Cercle of the Signes, or the Cercle

of the Bestes; for zodia in langage of Greek sowneth 'bestes' in

Latin tonge; and in the zodiak ben the twelve signes that ban

names of bestes; or elles, for whan the sonne entreth in any of the

signes, he taketh the propretee of swich bestes; or elles, for that

the sterres that ben there fixed [ben disposed in signes of bestes],

or shape like bestes; or elles, whan the planetes ben under thilke

signes, they causen us by hir influence operaciouns and effectes

lyk to the operaciouns of bestes. And understonde also, that whan

an hot planete cometh in-to an hot signe, than encresseth his hete;

and yif a planete be cold, thanne amenuseth his coldnesse, by-cause

of the hote signe. And by this conclusioun maystow take ensample

in alle the signes, be they moist or drye, or moeble or fix; rekening

[the qualitee of the planete] as I first seide. And everich of

thise twelve signes hath respecte to a certein parcelle of the body

of a man and hath it in governance; as Aries hath thyn heved, and

Taurus thy nekke and thy throte, Gemini thyn armholes and thyn

armes, and so forth; as shal be shewed more pleyn in the [fifte]

partie of this tretis. This zodiak, which that is part of the eighte

spere, over-kerveth the equinoxial; and he over-kerveth him again

in [evene parties]; and that on half declineth southward, and that

other northward, as pleynly declareth the tretis of the spere. And

for more declaracioun, lo here thy figure.

[22.] Thanne hastow a label, that is schapen lyk a rewle, save that

it is streit and hath no plates on either ende with holes; but, with

the smale point of the forseide label, shallow calcule thyne

equaciouns in the bordure of thin Astrolabie, as by thyn almury.

And for the more declaracioun, lo here thy figure.

[23.] Thyn Almury is cleped the Denticle of Capricorne, or elles

the Calculer. This same Almury sit fix in the bed of Capricorne,

and it serveth of many a necessarie conclusioun in equaciouns of

thinges, as shal be shewed; and for the more declaracioun, lo here

thy figure.

Here endeth the descripcion of the Astrolabie.