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# Title: [Lectiones XVIII, Cantabrigiae in Scholis publicis habitae] Lectiones XVIII, Cantabrigiæ in Scholis publicis habitæ (shelfmarks Leibn. Marg. 0; ZEN Leibn. Marg. 0)
# Folio 11, page id 797435492:0027
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# Model: FoNDUE-GD_v2_ft_Leibniz, run 74, 2026-09-06T16:05:13Z — 42 lines, status machine
# Lines: 42 recognised, mean confidence 0.95
# Machine transcription. Not an edition. Errors are expected: about 8% character error rate on Latin and French lines, higher on German.
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# After the first blank line: the recognised lines in reading order, one per line.

L, F C Y
quae circa radiorum inflectionem primitus obveniunt) existimo peren-
dam, quod lucis radius non mera sic linea, verum dimensionibus om
nimodis praeditum corpus; utpore (iuxta quae praemonuimus) cylin-
dricum aut prilnaticum, pro figura corpusculi, à quo oritur. Sup-
ponatur, aliquatenus illustrandi proxolici ergo, P’arallelexipedum
ABC D F FO HI lucis radium oblique speculo incurrentem reprx. F18. 3.
sentare; cujus latus B E applicetur lpeculo, duru interea reliquum
ejus supra speculi planum eleratur. Impedietur ergo Parallelogramum
ABFF, ne recta procedat; inde continget rectam B F aliquo supra
dictum planum resilire. Verum in allas saltem partes het haec reAe-
ctio, secundum quos rectus radii progressus, quoad ejus fieri porest,
quam minime pervertetur. Cum enim is restislimum cursum affecter
eum Cex indole certa, perpetuaque lege naturx) si pertecte nequit,
at tamen ut proxime consequetur. Ieaque cum inter plana latera
ABDC, E F HC sibimet oppolita cuxtus ejus antea dirigeretur, e
objecta superticies nihil jam oblter, quo minus inter eadem plana, ta-
metsi sursum excussus, progrediatur, admodum liquet criamnum inter
illa semitam ejus contineri. locumque seu placam refexionis eatenUS
haud perperam determinari. Cxteriim est planum ABDC, eique
oppolitum F FC II speculi plano rectum; quia Parallelepipedum
rectum ponitur, ec ideo lateralis recta B, F in speculi plano existens,
planis ABDC, FFHIC recta. Ouocirca litorum hoc Parallelecipedum
ob exilitatem luam, aut Mathematica computationis graria, prorecta
quasi linea censeatur, crir pariter e retterus radius etiam linea recta;
nec non uterque continebirur in superticie ad speculi planum recta.
Non dissimili rariocinio, Piradius cylindei recti ficura praeditus admie-
eatur (qualis nimirum a corpore procurrente, vel impulso producetur,
id Si Sphaericum Fuerit) etiam radius in superticie plano speculi recta
refectionem ostendetur subire. Speculi quippe plano rectus incidat
cxlindrus ABDC; cujus BaseS AMC N, BODP, avis XL; Fig. A
ita scilicet, ut balis BODP Speculi planum contingat in B. reli.
quum ejus corpus (prout in figura depictum exhibetur) oblique sur-
sens supra planum emineat. Balis autem diametri BD, PO Pese nOr-
maliter secent; ac per ipsam PO, E axem ductum planum efficiat in
exlindro Parallelogrammum POMVI. Si jam per hujusce latera
MO, NP ducta concipiantur duo plana axi parallela, cxlindrumque
concinsentia, liquebit (ex antedistis causis parirer applicatis) totius
eylindri ductum inter haec duo plana comprehendi, radiique reflecti.
onem inter ipsa definiri. Sine autem haec plana speculi plano recta.
Sic enim reisa GBMI communis sectio circuli BODP, planique
specubaris;