The most celebrated water throughout the whole world, and the one to which our city gives the palm for coolness and salu- brity, is that of the Marcian[1] Spring, accorded to Rome among the other bounties of the gods: the name formerly given to the stream was the "Aufeian," the spring itself being known as "Pitonia." It rises[2] at the extremity of the mountains of the Peligni, passes through the territory of the Marsi and through Lake Fucinus, and then, without deviating, makes directly for Rome: shortly after this, it loses itself in certain caverns, and only reappears in the territory of Tibur, from which it is brought to the City by an arched aqueduct nine miles in length. Ancus Marcius, one of the Roman kings, was the first[3] who thought of introducing this water into the City. At a later period, the works were repaired by Quintus Mar- cius Rex: and, more recently, in his prætorship, by M. Agrippa.[4]