Blank verso of the spring-engine sheet (folio 151v)
The verso bears no writing or drawings of its own; the catalogue note records that it was invisible before restoration, and only faint show-through of the engine studies on the recto can be seen.
Invisibile prima del restauro. Privo di scritti e disegni.
Invisible before restoration. Without writing or drawings.
Reader's Edition — described with AI from the e-Leo transcription.