laced, the one above the other, that numerous apertures were left for the fire to exhale at. Then I began to lay on wood by degrees, and kept it burning two whole days and nights. At length, when all the wax was gone, and the mould was well baked, I set to work at digging the pit in which to sink it. This I performed with scrupulous regard to all the rules of art. When I had finished that part of my work, I raised the mould by windlasses and stout ropes to a perpendicular position, and suspending it with the greatest care one cubit above the level of the furnace, so that it hung exactly above the middle of the pit, I next lowered it gently down into the very bottom of the furnace, and had it firmly placed with every possible precaution for its safety. When this delicate operation was accomplished, I began to bank it up with the earth I had excavated; and, ever as the earth grew higher, I introduced its proper air-vents, which were little tubes of earthen ware, such as folk use for drains and such-like purposes.[1] At length, I felt sure that it was admirably fixed, and that the filling-in of the pit and the placing of the air-vents had been properly performed. I also could see that my work-people understood my method, which differed very considerably from that of all the other masters in the trade. Feeling confident, then, that I could rely upon them, I next turned to my furnace, which I had filled with numerous pigs of copper and other bronze stuff! The
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- ↑ These air-vents, or sfiatatoi, were introduced into the outer mould, which Cellini calls the tonaca, or clay tunic laid upon the original model of baked clay and wax. They served the double purpose of drawing off the wax, whereby a space was left for the molten bronze to enter, and also of facilitating the penetration of this molten metal by allowing a free escape of air and gas from the outer mould.
