. Ioan Henrici Alstedii Scientiarum omnium encyclopædiæ : tomus primus [-quartus] ... . um femidiamctrilioc modo quxrustut pro diuerfis folaribus. Defctibatur infupethcie pL^na , vt in papyrp , quadrans Meridiani dlui-lus in 90 giadus more folito ; figneturque literis A B C. itavt AB. fuhneahotizont3lis,AC. fuper-ftcies crefta. Poftea numerctur elcuatio poli , in quadrantisarcu, a punfto C. verfusB. vel conira a punfto B. verfus eleuatio ^quinoftiahs , noteturque punao D.^quo pi-otrahatur linea ad punftam A, vbi eft angulus rc-Aas quadrantis: fitque linea A D ,
. Ioan Henrici Alstedii Scientiarum omnium encyclopædiæ : tomus primus [-quartus] ... . um femidiamctrilioc modo quxrustut pro diuerfis folaribus. Defctibatur infupethcie pL^na , vt in papyrp , quadrans Meridiani dlui-lus in 90 giadus more folito ; figneturque literis A B C. itavt AB. fuhneahotizont3lis,AC. fuper-ftcies crefta. Poftea numerctur elcuatio poli , in quadrantisarcu, a punfto C. verfusB. vel conira a punfto B. verfus eleuatio ^quinoftiahs , noteturque punao D.^quo pi-otrahatur linea ad punftam A, vbi eft angulus rc-Aas quadrantis: fitque linea A D , per quam ..^qmnoAialis, Poflremo duc lineam tranfuetfam , qmorthogonaliter intcrfecct ^quinodlialcm , in punifto quo-cunquc volueris: prout magnum aut paruuin inftitues faccreliorologium : vt v. g. in pundto linea FGE,qux repre-fcntet axcmmundi, & duo triangula fubtendat; ncmpe trian-gulum FA G , & G A E. Erit ergo lincj AE , femidiamcterhorologij hori^jontalis; linea AG , femidiameter horologiji£!is; §c AF fcmidiametcr horologij A IX. Inuenta femidiametro , fic fabricabis heri-<.ontalefolarium. Accipe fuperficicm planam, fiuc fit lamina , fiue tabula longitudo fit tripld maior eiufdcm latitudine : &pcr mediam tabulam duc lineam reftam , vt eft in fubie(^ofchemate linca AB , cuius mcdium pundtum fit C. Deindeouc lineam tranfuerfam,qux hanc priorem intcrfecat in pun-fto C , ad angulos rciftos. Poftea fupcr hanc lincam tranfuer-fam p E , dclcribc duos feraicirculos , qui (ek in pundo Qcontingant, quorum vnius, nempe .Equinoftiaiis femidia-metrum pete exquadrante , iam ante defcripto,nempe lineamAG , altcnus vero , ncmpc fuperioris femicirculi fcmidiame-trum capics ex eodem quadrante, puta per ILneam horizonta-lem AE. Ptiorem quidem fcmicirculum , vidclicet inferio,rem , fcu ^quinodlialcm ,dcfctibe fupcr centro E ; fuperio-rem , fiue centro fubtendet hne*vt M O : & hanc fupcriorcm claudet
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