The first calibration curve, published by Suess in 1967 (Suess 1967), was a wiggly thing arrived at by a process Suess called cosmic schwung. Later curves used more formal statistical methods, including Clark's published in <i>Antiquity</i> (1975), which came to be one of the most widely used. The newest calibration curves have been published in the calibration issue of Radiocarbon (Stuiver & Kra 1986), which takes 230 large-format pages to set them out as tables, graphs and a computer program. -- AATA