"A chariot, a car. These terms appear to have denoted those two wheeled vehicles for the carriage of persons, which were open overhead, thus differing from the corpentum, and closed in front, in which the differed from the cisium. The most essential articles in the construction of the currus were, 1. The rim. 2. The axle. 3. The wheels, which revolved upon the axle and were prevented from coming off by the insertion of pins into the extremities of the axles. The parts of the wheel were: a. The nave. b. The spokes. c. The felly. d. The tire. 4. The pole." — Smith, 1873. This picture shows a Quadrigae.