"Bridge from Pera to Constantinople. 40 braccia wide, 70 braccia high over the water, 600 braccia long, that is, 400 over the sea and 200 standing on the ground, providing its own support for itself."
The model represents a single span bridge that
ought to have measured 240 m long, 23 m
wide, and 40 m over the water level at its peak.
The two ends of the bridge each have a double,
swallow’s tail type support, providing better
resistance to transverse thrust. The drawing dates from Leonardo’s time in Romagna in service to Cesare Borgia and was executed probably in 1502, the year when the Ottoman ambassadors of Sultan Bayazid II were in Rome, looking for Italian engineers to substitute their old bridge made out of boats for crossing over the Golden Horn, with a new, more stable and lasting structure.
The model is based on the drawing:
- Manuscript L f. 66 r. (1502)
Paris, Institut de France