The publication cited in endnote 1 indicates that this roundel was made and engraved on a lathe. This, too, is wrong. Lathes that could perform such tasks did not exist in the Hellenistic age. See Paul Craddock and Janet Lang, “Spinning, Turning, Polishing,” Journal of the Historical Metallurgy Society (1983) 17/2 pp. 79–81; Robert S. Woodbury, “The Origins of the Lathe,” Scientific American 208:4 (1963), p. 132, and Studies in the History of Machine Tools: History of the Lathe to 1850(Cambridge, MA: MIT Press, 1972).