* Ctesias at the end of his work describes the route leading from Ephesus to Bactriana and India.  It is probable that the route described by Isidorus of Charax in his Stathma Parthica already existed in the times of the Achaemenids, and was traversed by their postal couriers.

** Mention of the Eye of the king occurs in Herodotus, in AEschylus, and in Plutarch, of the Ear in Xenophon; cf. the Persian proverb, according to which “The king has many eyes and many ears.”

     *** Xenophon affirms that these inspections were still held
     in his day.

[Illustration:  186.jpg Street Vender of Curios] After the Painting by Gerome.

A messenger would arrive unexpectedly, and remit to the guards an order charging them to put their chief to death—­an order which was promptly executed at the mere sight of the royal decree.

This reform in the method of government was displeasing to the Persian nobles, whose liberty of action it was designed to curtail, and they took their revenge in sneering at the obedience they could not refuse to render.  Cyrus, they said, had been a father, Cambyses a master, but Darius was only a pedler greedy of gain.  The chief reason for this division of the empire into provinces was, indeed, fiscal rather than political:  to arrange the incidence of taxation in his province, to collect the revenue in due time and forward the total amount to the imperial treasury, formed the fundamental duty of a satrap, to which all others had to yield.  Persia proper was exempt from the payment of any fixed sum, its inhabitants being merely required to offer presents to the king whenever he passed through their districts.  These semi-compulsory gifts were proportioned to the fortunes of the individual contributors; they might consist merely of an ox or a sheep, a little milk or cheese, some dates, a handful of flour, or some vegetables.  The other provinces, after being subjected to a careful survey, were assessed partly in money, partly in kind, according to their natural capacity or wealth.  The smallest amount of revenue raised in any province amounted to 170 talents of silver—­the sum, for instance, collected from Arachosia with its dependencies Gedrosia and Grandara; while Egypt yielded a revenue of 700 talents, and the amount furnished by Babylon, the wealthiest province of all, amounted to 1000 talents.  The total revenue of the empire reached the enormous sum of.L3,311,997, estimated by weight of silver, which is equivalent to over L26,000,000 of modern English money, if the greater value of silver in antiquity is taken into consideration.  In order to facilitate the collection of the revenue, Darius issued the gold and silver coins which are named after him.  On the obverse side these darics are stamped with a figure of the sovereign, armed with the bow or javelin.  They were coined on the scale of 3000 gold darics to one talent, each daric weighing normally.2788 oz. troy, and being worth exactly 20 silver drachmae or Medic shekels; so that the relative value of the two metals was approximately 1 to 13 1/2|.