[32], 489 (i.e. 493), [28] pp. Text in Latin and Italian in side-by-sided columns, with a separate title-page in each language. Illustrated with 79 copper engravings by Alexander Specus from the designs of Fontana, 8 fold-out, 2 double-page, the rest full page. (folio) 18¼x13¼, unbound and untrimmed signatures, set in modern folding cloth box.

Marvelous work on the architecture of the Vatican, specifically the Basilica of St. Peter's, including measured drawings and plans, fine engravings of the completed building, depictions of the various methods of construction, etc. The title in Italian is Tempio Vaticano e sua origine... In rare unbound state, the signatures untrimmed.