Detail of an X-radiograph of a dolphin’s body in which the denser welding zone appears as a brighter white area in the center, the rivets show up as small white donuts with darker centers, and porosity appears as black flecks. Great Dolphins of Vienne, Roman period, Vienne, France, 2nd century CE, max L. 260 cm (Musée des Beaux-Arts et d’Archéologie de Vienne, France, inv. R.1998.2.43). For a description of all visible technological evidence, refer to figs. 367, 467.