On display at the Museum of Gallo-Roman Civilization, this restored mosaic from Lugdunum (Lyon) vividly depicts a circus race. Eight chariots are competing, two from each faction, the quadrigae running around the track barrier, which consists of a channel or euripus filled with water. Here are placed the lap markers: seven dolphins, water gushing from their mouths, and seven eggs. When each lap had been run, a dolphin was tipped downward and an egg lowered from its bar (one can see that four laps already have been run). At the ends of the barrier are the turning posts (metae)on a detached plinth and, in the center, an obelisk. Between the basins, officials holding the palm branch and wreath of victory stand waiting, while a hortator rides ahead, setting the pace and assisting the charioteer. A sparsor holds a basin of water to refresh both horse and rider. (Basil, the bishop of Caesarea, actually speaks of water being thrown on the horses, when he writes about AD 375 that the arrival of a letter refreshed him "like water poured into the mouths of racehorses, inhaling dust with each eager breath at high noontide in the middle of the course," Epistle CCXXII.) The presiding magistrates can be seen above the starting gates protected by an awing, one holding the mappa that signaled the start of the race. Intriguingly, the figure next to the officials operates a lever, which may have released a latch that mechanically swung open the gates.

The white line (creta) on the left, where there has been an accident, is the break line, at which point, says Cassiodorus (Variae, III.51), the chariots could leave their lanes and move to an inside position, the intention being not so much to avert crashes as to prevent them from occurring before the race had fairly begun. A second white line, opposite the obelisk, marks the finish, the Lyon mosaic being the only one to depict both lines.

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