several thousand feet long, and contained some blocks weighing 

 fifteen tons. Traces of these rvigged walls were still visible as late 

 as the nineteenth century. 



North of Tyre is the small island of Arvad, a very early Phoeni- 

 cian colony whose engineers demonstrated to perfection their 

 ingenuity in coping with the sea. This island, where there was no 

 soil, no fresh water, and which was swept by storm waves, was 

 made to support human life. The engineers excavated lagoons to 

 act as wave traps on the seaward side of the island, and built apart- 

 ment houses many stories high. They even found a spring of fresh 

 water beneath the sea, not far from the island, and placed a lead 

 hemisphere over it. With a pipe led from the hemisphere to a boat 

 equipped with a storage tank. 



The early Phoenician and Carthaginian military harbors of North 

 Africa are of an interesting type called a cothon. These primitive 

 artificial basins were cut entirely out of the land so that the port 

 was snug within the city walls. Motya, on the west coast of Sicily, 

 and Utica, near Carthage, were both founded about 900 b.c, and 

 were on islands. The cothon at Utica was cut into the island and 

 measured 338 feet by 108 feet; that at Motya was 167 feet by 121 

 feet. 



Before the foundation of Carthage the island site of Utica had 

 already become too small and the city was expanding onto the 

 mainland. Here engineers built a greatly improved cothon, 781 

 feet by 607 feet, with rounded corners, a heavily fortified palace on 

 an island in the middle, and a strong breakwater to protect the sea- 

 ward side. The breakwater was ingeniously built with rows of 

 holes leading to a central channel or tunnel which ran within the 

 masonry along the entire length of the breakwater. This elaborate 

 system was most likely devised to reduce the shock of breaking 

 waves. The moles at Thapsus and Hadrumetum are of the same 

 design. 



-ett^^^JS^/ 



The "cothon," or military fortress of a 

 harbor, was an artificial basin cut into 

 the land. The plan of the one shown here 

 is for Utica, founded about 1000 B.c, 



As early as the ninth century B.C. men were 

 using artificial breathing apparatus for 

 underwater worl^. This relief shows Assyrian 

 divers with air tanl<s of inflated animal sl^ins. 



IJ3 



