This watercolor was painted by Carlo Bossoli during his years in Milan. The church represented here is Santa Maria alla Fontana, in front of which there was a large basin until 1877. It was said that the water in this fountain possessed a miraculous power. In the foreground the painting are two artisans of the Manfredini-Viscardi art foundry, who put the last touches on one of the Dioscuri, designed by Pelagio Pelagi. Crown the lattice that completes the Piazzetta Reale in front of the Royal Palace in Turin.
The art foundry was located next to the church of Santa Maria alla Fontana and in 1846 it filled the staues of bronze Dioscuri after the plaster models of San Giorgio (now in the Civic Museums of Bologna). The statues decorate since 1847 the great pillars on both sides of the entrance gate of the Royal Palace. The present lot represents a unique and pictorial testimony of the creation of these important bronzes.