Bronze is composed of copper with an alloy of about eight or ten per cent. of tin. The fusing of these two metals produces the brown glossy substance called bronze, which is so different from either of them. The art of the bronze caster is a very old and interesting one. The method of proceeding has varied very little with the centuries. A statue to be cast either in silver or bronze would be treated in the following manner. A general semblance of the finished work was first set up in clay; then over this a layer of wax was laid, as thick as the final bronze was intended to be. The wax was then worked with tools and by hand until it took on the exact form designed for the finished product. Then a crust of clay was laid over the wax; on this were added other coatings of clay, until quite a thick shell of clay surrounded the wax. The whole was then subjected to fervent heat, and the wax all melted out, leaving a space between the core and the outer shell. Into this space the liquid bronze was poured, and after it had cooled and hardened the outer shell was broken off, leaving the statue in bronze exactly as the wax had been. Cellini relates an experience in Paris, with an old man eighty years of age, one of the most famous bronze casters whom he had engaged to assist him in his work for Francis I. Something went wrong with the furnace, and the poor old man was so upset and "got into such a stew" that he fell upon the floor, and Benvenuto picked him up fancying him to be dead: "Howbeit," explains Cellini, "I had a great beaker of the choicest wine brought him,... I mixed a large bumper of wine for the old man, who was groaning away like anything, and I bade him most winning-wise to drink, and said: 'Drink, my father, for in yonder furnace has entered in a devil, who is making all this mischief, and, look you, we'll just let him bide there a couple of days, till he gets jolly well bored, and then will you and I together in the space of three hours firing, make this metal run, like so much batter, and without any exertion at all.' The old fellow drank and then I brought him some little dainties to eat: meat pasties they were, nicely peppered, and I made him take down four full goblets of wine. He was a man quite out of the ordinary, this, and a most lovable old thing, and what with my caresses and the virtue of the wine, I found him soon moaning away as much with joy as he had moaned before with grief." Cellini displayed in this incident his belief in the great principle that the artist should find pleasure in his work in order to impart to that work a really satisfactory quality, and did exactly the right thing at the right minute; instead of trusting to a faltering effort in a disheartened man, he cheered the old bronze founder up to such a pitch that after a day or two the work was completed with triumph and joy to both.