Anonymous, [Treatise on architecture and geometry] from the 17th century. 1 vol. in-8°: s.l.n.d., 61 leaves paginated 1-111, then 126, ruled. Numerous sketches in the text and 12 plates (p.70-81 finely drawn). Contemporary full parchment binding, slightly worn. Signature "Martin aîné" on upper flyleaf. Interesting manuscript produced by an architect to record his knowledge, then used in 1822 by a craftsman to record lists of days spent in preparation for writing briefs for payment claims. This kind of testimonial is all the more precious as few of these manuscripts have survived to the present day. Created out of necessity, in the face of prohibitive book prices that some architects and craftsmen could not afford, they contain both copies of entire chapters or sections of the great classic works of their time, and numerous handwritten notes that are just as valuable, as they supplement the theoretical knowledge of the time with often highly practical information.