Treatise on Twilight – Latin
- Title:
- De crepusculo matutino et vespertino
- Author:
- Ibn Muʿāḏ (Abhomad).
- Translation:
- anonymous.
- Transcribed from:
- Ibn Muʿāḏ (Abhomad), Alhazen filii Alhayzen De crepusculis et nubium ascensionibus liber unus, in: Ibn al-Hayṯam (Alhazen), Opticae thesaurus Alhazeni Arabis libri septem, ed. Friedrich Risner (Basel, 1572), pp. 283–288. Online at https://nbn-resolving.org/urn:nbn:de:bvb:12-bsb10197486-8.
- Transcribed by:
- Lenka Jiroušková.
- Download:
- TEI-XML
Contents
- ALHAZEN FILII ALHAYZEN DE CREPVSCVLIS ET NVBIVM ASCENSIONIBVS LIBER VNVS. Gerardo Cremonensi interprete.
- 1. Crepusculum matutinum incipit, ac uespertinum desinit, sole ante ortum et post occasum suum 19 partibus, in peripheria circuli per uerticem regionis solisque locum transeuntis, sub horizontem demerso.
- 2. Si sphaericum luminosum illuminet opacum aequale: hemisphaerium illuminabit. Vitell. 2 6 p 2.
- 3. Si sphaericum luminosum illuminet opacum minus: plus hemisphaerio illuminabit. Vitell. 27 p 2.
- 4. Si peripherias duorum circulorum aequalium duae rectae lineae tangant: puncta semiperipheriarum conuexis partibus se respicientium singula singulis apparent, reliquarum uero semiperipheriarum conuexis partibus se non respicientium latent.
- 5. De peripheria maximi in terra circuli sol illuminat partes 180, scrupula prima 27, scrupula secunda 52. Vitell. 59 p 10.
- 6. Posita peripheria maximi in terra circuli 24000 milliarium Italicorum. erit summa uaporum in nubem coactorum a terra altitudo 52000 passuum. Vitell. 60 p 10.