2. _Fenestella_, who died, according to Jerome, in A.D. 19 at the age of seventy. Nothing is known of his life, or of the poems which Jerome attributes to him; but he certainly wrote _Annales_ (Nonius, p. 154). He is also quoted as an authority on miscellaneous antiquarian and constitutional points. 3. _M. Verrius Flaccus_, tutor to the grandsons of Augustus (Sueton. _Gramm._ 17), was the author of _Fasti_, fragments of which have been discovered near Praeneste, and which were used by Ovid for his poem of that name. Of Verrius' grammatical works, the greatest was that entitled _De verborum significatu_ (Gell. v. 17, 1), arranged alphabetically. It is lost, but we possess part of an abridgment (nine out of sixteen Books) made by _Sex. Pompeius Festus_ before the third century A.D. The abridgment of Festus was in turn epitomized by _Paulus Diaconus_ in the time of Charlemagne, and his work is extant in a complete form. 4. _C. Iulius Hyginus_, a freedman of Augustus and librarian of the Palatine library (Sueton. _Gramm._ 20), wrote _De vita rebusque illustrium virorum_ (Gell. i. 14, 1); _Exempla_ (Gell. x. 18, 7); _De situ urbium Italicarum_ (Serv. _ad Verg. Aen._ iii. 553); _De familiis Troianis_ (ibid. v. 389); theological works, _e.g._ _De dis Penatibus_ (Macrob. _Saturn._ iii. 4, 13); commentaries on Virgil and Helvius Cinna; and _De Agricultura_, a treatise to which Virgil was indebted (Colum. i. 1, 13). The Hyginus who wrote _Fabulae_ and _De Astrologia_ probably lived in the second century A.D. VITRUVIUS. Vitruvius Pollio (the cognomen appears only in the abridgment of his book) served under Caesar in Africa B.C. 46; viii. 3, 25, 'C. Iulius Masinissae filius ... cum patre Caesari militavit. Is hospitio meo est usus. Ita cottidiano convictu necesse fuerat de philologia disputare ...' Under Augustus he was an officer of engineers, and was enabled to spend the rest of his life in comfort through the liberality of that prince and his sister Octavia: i. praef. 2, 'Cum M. Aurelio et P. Minidio et Cn. Cornelio ad apparationem ballistarum et scorpionum reliquorumque tormentorum refectionem fui praesto et cum eis commoda accepi. Quae cum primo mihi tribuisti, recognitionem per sororis commendationem servasti. Cum ergo eo beneficio essem obligatus, ut ad exitum vitae non haberem inopiae timorem ...' He wrote the treatise _De Architectura_, in ten Books, when he was no longer young (ii. praef. 4, 'faciem deformavit aetas'), between the years B.C. 16 and 13. The temple of Quirinus, mentioned iii. 2, 7, was built in the former year; and he speaks of only one stone theatre in Rome (iii. 2, 2), whereas in B.C. 13 there were three.