Standing 52 meters tall, Tour Saint-Jacques is the sole remaining Flamboyant Gothic tower of the 16th-century church of Saint-Jacques-de-la-Boucherie. Located near the home of legendary 14th-century alchemist Nicolas Flamel (who lived on Rue de Montmorency), the tower served as a sanctuary for alchemical experiments and astronomical observations by Blaise Pascal.
The full decipherment and its observational protocol — where to stand, when, and what to watch for — are in the Paris field codex.
Or read the complete Florence codex free first.