21. The Cloa'cae, or common sewers, attracted the wonder of the ancients themselves; the largest was completed by Tarquin the Proud. The innermost vault of this astonishing structure forms a semicircle eighteen Roman palms wide, and as many high: this is inclosed in a second vault, and that again in a third, all formed of hewn blocks of pepenno, fixed together without cement. So extensive were these channels, that in the reign of Augustus the city was subterraneously navigable. 22. The public roads were little inferior to the aqueducts and Cloa'cae in utility and costliness; the chief was the Appian road from Rome to Brundu'sium; it extended three hundred and fifty miles, and was paved with huge squares through its entire length. After the lapse of nineteen centuries many parts of it are still as perfect as when it was first made. 23. The Appian road passed through the following towns; Ari'cia, Fo'rum Ap'pii, An'xur or Terraci'na, Fun'di, Mintur'nae, Sinue'ssa, Cap'ua, Can'dium, Beneven'tum, Equotu'ticum, Herdo'nia, Canu'sium, Ba'rium, and Brundu'sium. Between Fo'rum Ap'pii and Terraci'na lie the celebrated Pomptine marshes, formed by the overflowing of some small streams. In the flourishing ages of Roman history these pestilential marshes did not exist, or were confined to a very limited space; but from the decline of the Roman empire, the waters gradually encroached, until the successful exertions made by the Pontiffs in modern times to arrest their baleful progress. Before the drainage of Pope Sixtus, the marshes covered at least thirteen thousand acres of ground, which in the earlier ages was the most fruitful portion of the Italian soil. _Questions for Examination_. 1. When was Rome founded? 2. What ceremonies were used in determining the pomcerium? 3. How was the comitium consecrated? 4. What was the first addition made to Rome? 5. What was the next addition? 6. Into what tribes were the Romans divided? 7. What were the hills added in later times to Rome? 8. Had the Romans any buildings north of the Tiber? 9. When did Rome become a magnificent city? 10. What was the extent of the city? 11. How was the city divided? 12. Which was the most remarkable of the seven hills? 13. What buildings were on the Capitoline hill? 14. What description is given of the forum? 15. Where was the senate-house and comitium? 16. What use was made of the Campus Martius? 17. What was the Pantheon? 18. Were the theatres and circii remarkable? 19. Had the Romans public baths? 20. How was the city supplied with water? 21. Were the cloacae remarkable for their size? 22. Which was the chief Italian road? 23. What were the most remarkable places on the Appian road? FOOTNOTES: