C i7 ) 
cofiflrmt quorum omnium (^emgnft rat tones ah Autlore cm-^ 
Jtihv crYimijf(£ fcictSme ex nvmc prvferendi^ conjeijui^fitkr 
Quod quatuor fentftr^ n7 hemi[ph^rlo uf dictum eH' 
extrucice fint jigum (^quala frmiles (rmiliter pofitce Jatis 
liquet^ reliqmm eH tit oftendamiu rehquam fuperjickm be- 
miffh(tricam tetragomfrni vere Geometnci ejjs capacem. 
Ad Flannm C A D B in punclo E erigi intelligatur fwr- 
mails retlaiequalis EA; & (tdper penpverlam x^CBD jt^ 
perfaies cyitndrka retla ejufdem altitud'inis, Fulgo notHm 
eH porttonei^ fuper^cie 't SphcertC(je inter qu(jelihet duo plana 
circulo A B C D paraJlela comprehenfarn cequaltm eQe por- 
tioni fuperjiciei cylindric^ inter eadem pla^a ; horum 
annulorum fimiles portiones refeilas k flanis in ereda ex E 
norwali fe mutuo interfecantihiu ejfe etiam equates. Si 
jam ducendo innumera plana lafi A C B D parade la dido 
modo deftgnari intelligantur in fuperficie cylindrica partes 
refpondentihus Sphceric 'is cequales^ quic e regione fuperficiei 
perforatione ahlatie dejignatur illi cequalis' esi ^ Quare patet 
refiduam a perforatione [uperfciem cequalem eJfe refidu^e fu- 
perficiei cylindrica dempta ilia quce e regione ahlatce per 
diiia iitnumera plana dejignatur. Ducat ur diameter qu^e^ 
lihet P M jecans peripheriam A H E utcmque in H. Jm- 
gatur H A^ p£r H ducat ur RT nor mails ad AB & pa- 
rallela ad CD per E du^am^ occurrens peripheric ACBD 
in K & T & peripheric A IE in I. Super K T diametro 
fiat femicir cuius cujus peripheric occur rant l\Sy I Q^ad 
KT normales in S Hujus femicirculi planum intel- 
ligatur normaliter ere^lum ad circulum^ A B C D, Z/nde 
peripheria R S QT erit in fuperficie hemtfpherica,^ re^aque 
H S nunc ad planum A G B D normalis^ erit altitudo fuper- 
ficiei cylindricc perforantis fupra hafeos punQum H. Idem- 
que de quolihet pun^o fuperficiei cylindricc perforantis ve^. 
rumeBy fiz.: ejus altitminem ufque ad fuperficiem Sphere 
fupra quodvis in haf pun^um hi, eJfe reilam H S,ut didum 
eB^genitam^fedVL S cqualis eft HA finui re£lo arms MA, 
^quQniam tarn hm quam ilia eji media Geometrica inter PH 
