Here begynneth the descripcioun of thin Astralabie.
Thyn Astrolabie hath a ring to putten onthe thombe of thi
right hond in taking the height of thinges. And tak kep, or from
henes forthward I wol clepen the heighte of any thing that is
taken by the rewle "the altitude," withoute moo wordes.
This ryng renneth in a maner toret fast to the moder
of thyn Astrelabie in so rowme a space that it distourbith not the
instrument to hangen after his right centre.
The moder of thin Astrelabye is thikkest plate,
perced with a large hool, that resceiveth in hir wombe the thynne plates
compowned for diverse clymates, and thy reet shapen in manere of
a nett or of a web of a loppe.
This moder is dividid on the bakhalf with a lyne that
cometh descending fro the ring doun to the netherist bordure. The
whiche lyne, fro the forseide ring unto the centre of the large
hool amidde, is clepid the south lyne, or ellis the lyne
meridional. And the remenaunt of this lyne doun to the bordure
is
clepid the north lyne, or ellis the lyne of
midnyght.
Overthwart this forseide longe lyne ther crossith him
another lyne of the same lengthe from eest to west. Of the whiche
lyne, from a litel cros (+) in the bordure unto the centre of the
large hool, is clepid the est lyne, or ellis the lyne orientale.
And the remenaunt of this lyne, fro the forseide centre unto the
bordure, is clepid the west lyne, or ellis the lyne occidentale.
Now hast thou here the foure quarters of thin Astrolabie divided
after the foure principales plages or quarters of the firmament.
The est syde of thyn Astrolabie is clepid the right syde,
and the west syde is clepid the left syde. Forget not thys, litel
Lowys. Put the ryng of thyn Astrolabie upon the thombe of thi
right hond, and than wol his right side be toward thi lift side,
and his left side wol be toward thy right side. Tak this rewle
generall, as wel on the bak as on the wombe syde. Upon the ende
of this est lyne, as I first seide, is marked a litel cros (+),
where as evere moo generaly is considerid the entring of the
first degre in which the sonne arisith.
Fro this litel cros (+) up to the ende of the lyne
meridionall, under the ryng, shalt thou fynden the bordure
divided with 90 degrees; and by that same proporcioun is every
quarter of thin Astrolabie divided. Over the whiche degrees there
ben noumbres of augrym that dividen thilke same degres fro 5 to
5, as shewith by longe strikes bitwene. Of whiche longe strikes
the space bitwene contenith a myle wey, and every degre of the
bordure conteneth 4 minutes; this is to seien, mynutes of an
houre.
Under the compas of thilke degrees ben writen the
names of the 12 Signes: as Aries, Taurus, Gemini, Cancer, Leo, Virgo,
Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Piscis. And
the nombres of the degrees of thoo signes be writen in augrym
above, and with longe divisiouns fro 5 to 5, dyvidid fro the ryme
that the signe entrith unto the last ende. But understond wel
that these degres of signes ben everich of hem considred of 60
mynutes, and every mynute of 60 secundes, and so furth into smale
fraccions infinite, as saith Alkabucius. And therfore knowe wel
that a degre of the bordure contenith 4 minutes, and a degre of
a signe conteneth 60 minutes, and have this in mynde.
Next this folewith the cercle of the daies, that ben
figured in manere of degres, that contenen in nomhre 365, dividid
also with longe strikes fro 5 to 5, and the nombre in augrym
writen under that cercle.
Next the cercle of the daies folewith the
cercle of the names of the monthes, that is to say, Januarius,
Februarius, Marcius, Aprilis, Maius, Junius, Julius, Augustus,
September, October, November, December. The names of these
monthes were clepid somme for her propirtees and somme by
statutes of Arabiens, somme by othre lordes of Rome. Eke of these
monthes, as liked to Julius Cesar and to Cesar Augustus, somme
were compouned of diverse nombres of daies, as Julie and August.
Than hath Januarie 31 daies, Februarie 28, March 31, Aprill 30,
May 31, Junius 30, Julius 31, Augustus 31, Septembre 30, Octobre
31, Novembre 30, Decembre 31. Natheles, all though that Julius
Cesar toke 2 daies out of Feverer and putte hem in his month of
Juyll, and Augustus Cesar clepid the month of August after his
name and ordeined it of 31 daies, yit truste wel that the sonne
dwellith therfore nevere the more ne lasse in oon signe than in
another.
Than folewen the names of the holy daies in the
Kalender, and next hem the lettres of the A B C on whiche thei fallen.
Next the forseide cercle of the A B C, under the
cross lyne, is marked the skale in manere of 2 squyres, or ellis in
manere of laddres, that serveth by his 12 pointes and his
dyvisiouns of ful many a subtil conclusioun. Of this forseide
skale fro the cross lyne unto the verrey angle is clepid Umbra
Versa, and the nethir partie is clepid Umbra Recta, or ellis
Umbra Extensa.
Than hast thou a brod reule, that hath on either
ende a square plate perced with certein holes, somme more and somme
lasse, to resceyve the stremes of the sonne by day, and eke by
mediacioun of thin eye to knowe the altitude of sterres by night.
Than is there a large pyn in manere of an extre,
that goth thorugh the hole that halt the tables of the clymates and the
riet in the wombe of the moder; thorugh which pyn ther goth a
litel wegge, which that is clepid the hors, that streynith all
these parties to-hepe. Thys forseide grete pyn in manere of an
extre is ymagyned to be the Pool Artik in thyn Astralabie.
The wombe syde of thyn Astrelabie is also divided
with a longe cros in 4 quarters from est to west, fro southe to northe,
fro right syde to left side, as is the bakside.
The bordure of which wombe side is divided fro the
point of the est lyne unto the point of the south lyne under the ring,
in 90 degrees; and by that same proporcioun is every quarter
divided, as is the bakside. That amountith 360 degrees. And
understond wel that degres of this bordure ben aunswering and
consentrike to the degrees of the equinoxiall, that is dividid
in the same nombre as every
othir cercle is in the highe hevene. This same bordure is divided also with 23 lettres
capitals and a small cross (+) above the south lyne, that shewith
the 24 houres equals of the clokke. And, as I have seid, 5 of
these degres maken a myle wey, and 3 mile-wei maken an houre. And
every degre of thys bordure contenith 4 minutes, and every minute
60 secundes. Now have I told the twyes.
The plate under the riet is discrived with 3
cercles, of whiche the leest is clepid the cercle of Cancre by cause that the
heved of Cancre turnith evermo consentrik upon the same cercle.
In this heved of Cancer is the grettist declinacioun northward
of the sonne, and therfore is he clepid solsticium of somer;
which declinacioun, after Ptholome, is 23 degrees and 50 minutes
as wel in Cancer as in Capricorn. This signe of Cancer is clepid
the tropik of somer, of tropos, that
is to seien "ageynward." For than beginneth the sonne to passen from
us-ward.
The myddel cercle in wydnesse, of these 3, is clepid the
cercle equinoxiall, upon which turnith evermo the hevedes of
Aries and Libra. And understond wel that evermo thys cercle
equinoxiall turnith justly from verrey est to verrey west as I
have shewed the in the speer solide. This same cercle is clepid
also Equator, that is the weyer of the day; for whan the sonne
is in the hevedes of Aries and Libra, than ben the dayes and the
nightes ylike of lengthe in all the world. And therfore ben these
2 signes called the equinoxiis. And all that moeveth withinne the
hevedes of these Aries and Libra, his moevyng is clepid
northward; and all that moevith withoute these hevedes, his
moevyng is clepid southward, as fro the equinoxiall. Tak kep of
these latitudes north and south, and forget it nat. By this
cercle equinoxiall ben considred the 24 houres of the clokke; for
evermo the arisyng of 15 degrees of the equinoxiall makith an
houre equal of the clokke. This equinoxiall is clepid the gurdel
of the first moeving, or ellis of the firste moevable. And note
that the firste moevyng is clepid moevyng of the firste moevable
of the 8 speer, which moeving is from est to west, and eft ageyn
into est. Also it is clepid girdel of the firste moeving for it
departith the firste moevable, that is to seyn the spere, in two
like partyes evene distantz fro the poles of this world.
The widest of these 3 principale cercles is clepid the
cercle of Capricorne, by cause that the heved of Capricorne turneth
evermo consentrik upon the same cercle. In the heved of this
forseide Capricorne is the grettist declinacioun southward of the
sonne, and therfore it is clepid the solsticium of wynter. This
signe of Capricorne is also clepid the
tropic of wynter, for than begynneth the sonne to come ageyn to us-ward.
Upon this forseide plate ben compassed certeyn
cercles that highten almycanteras, of whiche somme of hem semen parfit
cercles and somme semen inparfit. The centre that stondith
amyddes the narwest cercle is clepid the cenyth. And the
netherist cercle, or the firste cercle, is clepid the orizonte,
that is to seyn, the cercle that divideth the two emysperies,
that is, the partie of the hevene above the erthe and the partie
bynethe. These almykanteras ben compowned by 2 and 2, all be it
so that on diverse Astrelabies somme almykanteras ben divided by
oon, and somme by two, and somme by thre, after the quantite of
the Astrelabie. This forseide cenyth is ymagined to ben the
verrey point over the crowne of thin heved. And also this cenyth
is the verray pool of the orizonte in every regioun.
From this cenyth, as it semeth, there comen a maner
croked strikes like to the clawes of a loppe, or elles like the werk of
a wommans calle, in kervyng overthwart the almykanteras. And
these same strikes or divisiouns ben clepid azimutz, and thei
dividen the orisounte of thin Astrelabie in 24 divisiouns. And
these azymutz serven to knowe the costes of the firmament, and
to othre conclusions, as for to knowe the cenyth of the sonne and
of every sterre.
Next these azymutz, under the cercle of Cancer, ben
there 12 divisiouns embelif, muche like to the shap of the azemutz,
that shewen the spaces of the houres of planetes.
The riet of thin Astrelabie with thy zodiak, shapen
in manere of a net or of a lopweb after the olde descripcioun, which
thou maist turnen up and doun as thiself liketh, contenith
certein nombre of steires fixes, with her longitudes and
latitudes determinat, yf so be that the maker have not errid. The
names of the sterres ben writen in the margyn of the riet there
as thei sitte, of whiche sterres the smale point is clepid the
centre. And understond also that alle the sterres sitting within
the zodiak of thin Astrelabie ben clepid sterres of the north,
for thei arise by northe the est lyne. And all the remenaunt
fixed oute of the zodiak ben clepid sterres of the south. But I
seie not that thei arisen alle by southe the est lyne; witnesse
on Aldeberan and Algomeysa. Generaly understond this
rewle, that thilke sterres that ben clepid sterres of the
north arisen rather than the degre of her longitude, and alle the
sterres of the south arisen after the degre of her longitude—
this is to seyn, sterres fixed in thyn Astrelabie. 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 be
lyne-right, or ellis in the superficie of this lyne, than is the
eclipse of the sonne or of the mone, as I shal declare, and eke
the cause why. But sothly the ecliptik lyne of thy zodiak is the
utterist bordure of thy zodiak there the degrees be marked.
Thy zodiak of thin Astrelabie is shapen as a compas which
that contenith a large brede as after the quantite of thyn Astrelabie,
in ensample that the zodiak in hevene is ymagyned to ben a
superfice contenyng a latitude of 12 degrees, whereas alle the
remenaunt of cercles in the hevene ben ymagyned verrey lynes
withoute eny latitude. Amiddes this celestial zodiak is ymagined
a lyne which that is clepid the ecliptik lyne, under which lyne
is evermo the wey of the sonne. Thus ben there 6 degres of the
zodiak on that oo syde of the lyne and 6 degrees on that othir.
This zodiak is dividid in 12 principale divisiouns that departen
the 12 signes, and, for the streitnesse of thin Astrolabie, than
is every smal divisioun in a signe departed by two degrees and
two, I mene degrees contenyng 60 mynutes. And this forseide
hevenysshe zodiak is clepid the cercle of the signes, or the
cercle of the bestes, for "zodia" in langage of Grek
sowneth "bestes" in Latyn tunge. And in the zodiak ben the 12
signes that han names of bestes, or ellis for whan the sonne entrith in eny
of tho signes he takith the propirte of suche bestes, or ellis
for that the sterres that ben ther fixed ben disposid in signes
of bestes or shape like bestes, or elles whan the planetes ben
under thilke signes thei causen us by her influence operaciouns
and effectes like to the operaciouns of bestes.
And understond also that whan an hot planete cometh into an
hot signe, than encrescith his hete; and yf a planete be cold,
than amenusith his coldnesse by cause of the hoote sygne. And by
thys conclusioun maist thou take ensample in alle the signes, be
thei moist or drie, or moeble or fixe, reknyng the qualite of the
planete as I first seide. And everich of these 12 signes hath
respect to a certeyn
parcel of the body of a man, and
hath it in governaunce; as Aries hath thin heved, and Taurus thy
nekke and thy throte, Gemini thin armholes and thin armes, and
so furth, as shall be shewid more pleyn in the 5 partie of this
tretis.
This zodiak, which that is part of the 8 speer, over-kervith
the equinoxial, and he over-kervith him ageyn in evene parties;
and that oo half declineth southward; and that othir northward,
as pleinly declarith the Tretys of the Speer.
Than hast thou a label that is shapen like a reule, save
that it is streit and hath no plates on either ende with holes. But
with the smale point of the forseide label shalt thou calcule
thin equaciouns in the bordure of thin Astralabie, as by thin
almury.
Thin almury is clepid the denticle of Capricorne, or ellis
the calculer. This same almury sitt fix in the heved of Capricorne,
and it serveth of many a necessarie conclusioun in equacions of
thinges as shal be shewid.
Here endith the descripcioun of the Astrelabie and here begynne the conclusions of the Astrelabie.
