Corpus of Electronic Texts Edition
An Irish Astronomical Tract (Author: [unknown])

Caibidil 24

Dico quod Luna Soli quasam eclipsis etcetera.

.i. Aderim gorab e an re as cuis d'eclipsis na greine oir as i a speir speir as ichtaraighe sis do na speirib nemda & as si speir na greine an cethramad speir don taib tuas de sin & mar sin gach sibal dani as fai grein bhis. Et an uair tecmas se a cinn no a n-earball na Dreaguine a n-en ceim co direach ris in n-grein gan claenad da deiscert na da tuaiscert, boinid solus na greine dinne & is e an dorcadus sin as eclipsis ann. An trat cheana claenas da let deis no cli & nac sibhlaiginn co direch a ceann no a n-earball na Dreaguine fa grein a n-en ceim re secnaidh annsin eclipsis da tuismeadh. Et as e corp an re an docardus so daciter sa grein an uair eclipsis do beith ann, ma sedh as follus nac tic eclipsis ann co brach acht an trat bis an re fon grein co direach a n-en ceim re & is annsa leth tiar da grein tinnscnas se co brac & thoir crichnaiges. Et an trat siblaighes an re dan taibh amuith dan ceim direach sin na greine dorcaidh, uair ann, cuid don grein orainn. Et as ime sin atait da ghne ag eclipsis na greine mar ata ac eclipsis an re .i. eclipsis uili & eclipsis rannaighi.

Et da rer examlacht na crich bit an t-eclipsis co h-egsamail inntu , oir an trat bis eclipsis ann ni comtrom daciter e an gach cric oir ata cric a faicter e & cric nach faicter & crich a faicter nis mo & cric a faicter nis lugha amail ata so; .i. da m-bedh an grian is an line direach os ar cinn an airdi & an re is in line cedna fuithi da badh egin eclipsis ann duinne. Et da m-bedh neach is an uair cedna a n-oirrcer an domuin & e ac fecain na greine, dacitfedh , dar leis, hi an iartar an domain. Et da m-bedh nec ele isin uair cedna a n-iartar an domain ac fecain na greine, dacithfedh se, dar leis, hi


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a n-oirrcer in domain; gihedh ni faicinn ceachtar acu eclipsis na greine, oir da rachadh radharc gac neac acu co direc idir an grein & in re & mar sin ni boinfedh an re, ge da bedh se isin line direc fa grein ar a fad san on line sin na en corp dorcha, solus na greine dib. Et an pinnsi a n-dorcaiter an grian mar sin daciter innti sa lo na h-airdrinnaig le med an dorcadais.

Et as girra beris as eclipsis na greine na eclipsis an re le na luas ar aen ac dul tar a ceili & ni mar sin ata eclipsis an re noch thic on talmain, ni bhi 'ga chur as ach sibal an re 'na aenur & in talam 'na comhnaighe.

Et gibe neach da ticfadh in ar n-agaid annso & aderadh na budh e an re bud cuis d'eclipsis na greine & da mud e mar adubrumar, na budh chora do san eclipsis da dhenamh na da Uenir & da Mercuir an trat bid sa line direc fai grein. Et as do sin freagramaid, oir an trat bis Uenir & Mercuir fai grein a n-en ceim re as ar fad bis, gidedh as annsin teit uaithe a meid & a letead & is minic theagmas an i cedna don re oir bi fai grein co minic a n-en ceim ria ar fad & gidhed bith a fad uaithe ar lethed.

Amail nach tic eclipsis na greine o na retlannaib as ludha corp na'n re & is foicsi dhi, oir an trat curtar corp bec fa corp mhor a fogus do, gach foicsi da m-bi do as lughaidi fhoilghis de, & trat curtar a fad on corp mor e & a fogus don radharc bis ac a fecain araen, gach fad doteit on corp mor & gach foicsi dateit don radharc , is moidi foilghes an corp mor, innas gorab mar sin co foileocadh uball fiadain corp na greine ar in radarc.

Et da cur so a ceill dagen fidair annso tis a n-dingean


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cercall mor amail cercall na greine & cuirfed an grian na 'mullach tuas & dagen cercall ele don leth istigh di sin amail cercall an re & cuirfed an re fein 'na mullach thuas annsa line direc fa grein & dagen an tres cercall don taibh astigh di sin ar cuma na talman & cuirfed E litir 'na seantrom & saimeolad e risin inadh sa talmain as a faicid na daine an grian & cuirfed A a n-oirrcer & cuirfed B a n-iartar speiri na greine & cuirfed radarc na n-daine is in line direch o E & o A & o B cum na greine. Ma sedh na daine ata a n-E dacit siat eclipsis na greine co follus. Et an buiden cedna ata a n-A & a m-B, dacit co follus an grian gan eclipsis, oir ata an re robec a fecain na greine . Ni folaidinn an grian orta & is uime sin ar a fad san on grein teit a radarc co h-urusa don taib thuas don re d'innsaighi na greine.

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