This article reconstructs an exceptional lifting device — a cruciform lewis — drawn by Antonio da Sangallo the Younger (1484–1546) at St Peter’s Basilica in Rome and connects it to the other drawings, mainly of Vitruvian theory, on the same sheet (now in the Uffizi in Florence). Elements of this sheet, dated to January 1542, have been studied in isolation, but this article connects them, underscoring how Sangallo’s theoretical interests in the art of building and the practicalities of masonry construction were inseparable. A question posed by the sheet is whether it documents Sangallo’s archaeological discoveries of ancient Roman tools or presents newly contrived ones — categories that Sangallo’s drawings move fluidly between. His studies should be understood in relation to the immediate problems that he faced on the building site of St Peter’s and within the broader context of other Renaissance drawings of machines, such as those by Francesco di Giorgio and Leonardo da Vinci.