There are a number of books of machines that remain unpublished. There's the anonymous Rosenwald Renaissance sketchbook featuring machines and fortifications. There's also the book written by Jacques Gentillâtre.
Born in 1587, Gentillâtre worked as an architect, engineer, and engraver. He started his career in the atelier of Jacques II Du Cerceau and went on to work in various locations in France and in Geneva. RIBA holds a collection of almost 300 of his designs, executed between 1597 and 1623. Of more interest, however, is a manuscript book contained in the Bibliotheque Nationale (MS. fr. 14727). This work contains four different sections. The first is devoted to math, including pages devoted to surveying and to tables of common mathematical functions such as addition and subtraction. The second section contains designs for both fortifications and war machines. It was largely influenced by other treatises such as those by Errard and Durer. The third section contains building designs and commentary on architectural theory. In addition to theory, Gentillâtre gives some guidance on those common tacit elements of construction: masonry and carpentry (two disciplines that were primarily organized and controlled by guilds). The fourth and final section is devoted to mechanical inventions. For the most part, his inventions aren't new. Rather, they are rehashed from the examples of De Caus, Errard, Besson, and Ramelli.
One thing is missing from this work. Unlike contemporary sketchbooks there are no drawings of classical ruins. It seems that Gentillâtre was looking forwards for his inspiration rather than backwards.
It's unclear what role this book had. Perhaps it was intended to be a tool for winning a patron that never emerged. Or perhaps it served as a portfolio that demonstrated Jacques Gentillâtre's competence in all areas of architectural/engineering theory. The role of the section on machines is particularly interesting. Why machines? They certainly captured the imagination of many individuals but the actual execution of the devices was inevitably dependent upon the skills of craftsmen rather than fancy designs. But which craftsmen? Unlike other practices of architecture there was no guild of machine builders to dictate the actual execution of a project. This situation may also have applied to other projects such as roads and canals (often executed by serfs) and military facilities. Were machines simply a way for engineers to break through the dominant positions of masons (for project execution) and architects (for humanistic discourse)?
Châtelet-Lange, Liliane (1988). "L'architecte entre science et practique: le cas de Jacques Gentillâtre." In Andre Chastel and Jean Guillaume (eds.) Les traites d'architecture de la Renaissance, pgs 397-406. Picard: Paris.