Religion provided an important influence during the Dark Ages (circa 400 to 1400) for perpetuating the foundryman’s skills. Construction of cathedrals and churches required the casting of bells that were used in these structures. Indeed , the time and effort needed to cast the large bronze bells of the realm of art toward the regimen of technology. Advances in melting and mold-making techniques were made. Pit molding, in which the molds were formed in a deep pit located in front of furnace to simplify the pouring process, was improved as a casting procedure. In addition, the bell founder learned the relationships between the tone of the bell, which was the important measure of product quality, and its size, shape, thickness, and metal composition.