the attack with arms in rest, the onset was made first with separate squadrons, and then in entire masses.[431] The Medes and Persians had learned the art of siege from the Assyrians. The cities were enclosed by ramparts, and on these works were carried forward, under the protection of which battering-rams were brought to bear against the trenches and walls. The Persians were also well acquainted with mining. Passages were carried under-ground, both to make breaches in the walls by excavations, and to provide a way into the city. In order to recapture Chalcedon, which had rebelled against Darius when he crossed the Danube against the Scythians, together with the cities of the Propontis and Hellespont, an under-ground passage of more than 15 stades in length was carried, after the king's return, under the walls of the city to the market-place, and the Chalcedonians had no suspicion of its existence, till the Persians appeared in the city.[432] FOOTNOTES: [369] In his "Metrological Studies" Böckh fixed the ratio of the Euboean to the Babylonian talent as 5:6. Since that time the discovery of numerous gold and silver Persian coins and of weights at Babylon and Nineveh, and the lion of Abydus with its Aramaean stamp, have provided the means for fixing the gold talent of Darius at 25,245 kilogrammes, and his silver talent (the Babylonian talent) at 33,660 kilogrammes; Brandis, "Münzwesen," s. 54, 63, 64, 69. Hence Brandis takes Mommsen's view, that in Herod. 3, 89, 95, we must read 78 instead of 70 Euboean talents; the Euboean talent in Attica was a little heavier than the light Babylonian talent (the gold talent of Darius), and in the calculation 7600 Babylonian talents must be made equal to 9880 Euboean talents, which enables us to preserve the total sum given by Herodotus--14,560 talents. [370] Brandis, "Münzwesen," s. 225, 231, 239, 241. [371] Herod. 3, 96; Strabo, p. 735. [372] Herod. 3, 89; Xenoph. "Hellen." 3, 4, 25. [373] Herod. 6, 42. [374] Herod. 1, 192; Böckh, "Staatshaush." 1^2, 130. [375] Herod. 3, 117; 2, 149. [376] Herod. 1, 192. [377] Strabo, p. 525. [378] Xenoph. "Anab." 4, 5, 34 ff. [379] Herod. 3, 91; Böckh, "Staatshaush." 1^2, 135. [380] Xenoph. "Cyri Inst." 8, 6, 23; Athenaeus, p. 145, 146. [381] Strabo, p. 735. [382] In Athenaeus, p. 145. [383] _Loc. cit._ in Athenaeus. [384] Herod. 7, 118; Plut. "Artax." c. 4, 5. [385] In Athenaeus, p. 146. [386] Herod. 1, 192. [387] Herod. 9, 109; Xenoph. "Anab." 1, 4, 9; 2, 4, 27; Plato, "Alcib. I." p. 123; Cic. "In Verrem," 3, 33. [388] Xenoph. "Cyri Inst." 8, 6, 5.