Ornaments in iron were sometimes cut out of flat sheet metal, and then hammered into form. In stamping this flat work with embossed effect, the smith had to work while the iron was hot,--as Sancho Panza expressed it, "Praying to God and hammering away." Dies were made, after a time, into which the design could be beaten with less effort than in the original method. One of the quaintest of iron doors is at Krems, where the gate is made up of square sheets of iron, cut into rude pierced designs, giving scenes from the New Testament, and hammered up so as to be slightly embossed. The Guild of Blacksmiths in Florence flourished as early as the thirteenth century. It covered workers in many metals, copper, iron, brass, and pewter included. Among the rules of the Guild was one permitting members to work for ready money only. They were not allowed to advertise by street crying, and were fined if they did so. The Arms of the Guild was a pair of furnace tongs upon a white field. Among the products of the forge most in demand were the iron window-gratings so invariable on all houses, and called by Michelangelo "kneeling windows," on account of the bulging shape of the lower parts. One famous iron worker carried out the law of the Guild both in spirit and letter to the extent of insisting upon payment in advance! This was Nicolo Grosso, who worked about 1499. Vasari calls him the "money grabber." His specialty was to make the beautiful torch holders and lanterns such as one sees on the Strozzi Palace and in the Bargello. In England there were Guilds of Blacksmiths; in Middlesex one was started in 1434, and members were known as "in the worship of St. Eloi." Members were alluded to as "Brethren and Sisteren,"--this term would fill a much felt vacancy! Some of the Guilds exacted fines from all members who did not pay a proper proportion of their earnings to the Church. Another general use of iron for artistic purposes was in the manufacture of grilles. Grilles were used in France and England in cathedrals. The earliest Christian grille is a pierced bronze screen in the Church of the Nativity in Bethlehem. In Hildesheim is an original form of grille; the leaves and rosettes in the design are pierced, instead of being beaten up into bosses. This probably came from the fact that the German smith did not understand the Frankish drawing, and supposed that the shaded portions of the work were intended to be open work. The result, however, is most happy, and a new feature was thus introduced into grille work. [Illustration: WROUGHT IRON FROM THE BARGELLO, FLORENCE] Many grilles were formed by the smith's taking an iron bar and, under the intense heat, splitting it into various branches, each of which should be twisted in a different way. Another method was to use the single slighter bar for the foundation of the design, and welding on other volutes of similar thickness to make the scroll work associated with wrought iron.