Overview Level of Folio 53 r


Size Height 291 mm, width 206 mm.
Watermark Eagle encircled with crown outside. Drake's identification: Watermark type 20. Drake's description: Speadeagle in 40mm circle, crown above. Watermark found in 1611-34.
Comments Written by Arrighetti with an addition by Galileo; contains texts, drawing. Copied from folio 140r. Relation to the Discorsi: elaboration of 2/30-th-19; incomplete draft (statement) of 2/30-th-19.
Folio 53 r (final text)
1A Sit linea horizontis ac, perpendiculum vero bd, et in ac accipiatur quodcumque punctum c: dico, quod si mobile debet ex c ad lineam perpendiculi naturaliter per unicam lineam rectam moveri, ad eam perveniet tempore brevissimo si veniat per ce, quae lineam be, ipsi bc aequalem, assumit.
1B Centro enim b, intervallo be, circulus describatur, ductisque cf et cg utcumque, patebit motum per ce citius absolvi quam per cf aut cg. Si enim ducatur tangens circulum ick, et ipsi cf parallela elk, erit le brevior quam cf: sed tempus per ce aequatur tempori per le. Similiter, ducta ehi ipsi cg parallela et aequali, constat cg longiorem esse he: at tempus per ce aequatur tempori per he. Ergo patet propositum.
2 Si ex aliquo puncto in orizontali sumpto descendat perpendiculum, ex alio vero puncto eiusdem orizontis ducendum sit usque ad perpendiculum planum per quod brevissimo tempore mobile descendat, tale planum erit illud quod de perpendiculo abscindit partem [a]equalem distantiae pu[n]cti accepti in orizonte a primo puncto perpendiculi.


Overview Level of Folio 53 r