15 cm mortar, 1838 model

At the end of the 1830s, the French artillery adopted four calibers of mortar to replace the firearms of the same type previously used in their siege sector. Calibers were henceforth provided in centimeters: the 32 cm mortar replaced the 12-inch mortar, the 27 cm mortar replaced the 10-inch mortar, the 22 cm mortar replaced the 8-inch mortar, and a new 15 cm caliber (based on the measurements of the 6-inch bomb) was adopted for use. This last caliber, the lightest, was positioned on a wooden gun carriage base with rings, which facilitate its deployment in theaters.