§332. The Arena.--The arena is the level space surrounded by the seats and the barriers. The name was derived from the sand used to cover its surface to spare as much as possible the unshod feet of the horses. A glance at the plan will show that speed could not have been the important thing with the Romans that it is with us. The sand, the shortness of the stretches, and the sharp turns between them were all against great speed. The Roman found his excitement in the danger of the race. In every representation of the race course that has come down to us may be seen broken chariots, fallen horses, and drivers under wheels and hoofs. The distance was not a matter of close measurement either, but varied in the several circuses, the Circus Maximus being fully 300 feet longer than the Circus of Maxentius. All seem to have had constant, however, the number of laps, seven to the race, and this also goes to prove that the danger was the chief element in the popularity of the contests. The distance actually traversed in the Circus of Maxentius may be very closely estimated. The length of the _spīna_ is about 950 feet. If we allow fifty feet for the turn at each _mēta_, each lap makes a distance of 2,000 feet, and six laps, 12,000 feet. The seventh lap had but one turn in it, but the final stretch to the _calx_ made it perhaps 300 feet longer than one of the others, say 2,300 feet. This gives a total of 14,300 feet for the whole _missus_, or about 2.7 miles. Jordan calculates the _missus_ of the Circus Maximus at 8.4 kilometers, which would be about 5.2 miles, but he seems to have taken the whole length of the arena into account, instead of that merely of the _spīna_. [Illustration: FIGURE 141. THE CARCERES] §333. The Barriers.--The _carcerēs_ were the stations of the chariots and teams when ready for the races to begin. They were a series of vaulted chambers entirely separated from each other by solid walls, and closed behind by doors through which the chariots entered. The front of the chamber was formed by double doors, with the upper part made of grated bars, admitting the only light which it received. From this arrangement the name _carcer_ was derived. Each chamber was large enough to hold a chariot with its team, and as a team was composed sometimes of as many as seven horses the "prison" must have been nearly square. There was always a separate chamber for each chariot. Up to the time of Domitian the highest number of chariots was eight, but after his time as many as twelve sometimes entered the same race, and twelve _carcerēs_ had, therefore, to be provided, although four chariots was the usual number. Half of these chambers lay to the right, half to the left of the _porta pompae_. The appearance of a section of the _carcerēs_ is shown in Fig. 141. [Illustration: FIGURE 142. BOX OF THE DATOR LUDORUM]