Travellers had discovered inscriptions engraved in cuneiform, or, as they were also termed, arrow-headed, characters on the ruined monuments of Persepolis and other ancient sites in Persia. Some of these monuments were known to have been erected by the Achæmenian princes—Darius, the son of Hystaspes, and his successors—and it was therefore inferred that the inscriptions also had been carved by order of the same kings. The inscriptions were in three different systems of cuneiform writing; and, since the three kinds of inscription were always placed side by side, it was evident that they represented different versions of the same text. The subjects of the Persian kings belonged to more than one race, and just as in the present day a Turkish pasha in the East has to publish an edict in Turkish, Arabic, and Persian, if it is to be understood by all the populations under his charge, so the Persian kings were obliged to use the language and system of writing peculiar to each of the nations they governed, whenever they wished their proclamations to be read and understood by them. It was clear that the three versions of the Achæmenian inscriptions were addressed to the three chief populations of the Persian Empire, and that the one which invariably came first was composed in ancient Persian, the language of the sovereign himself. Now this Persian version happened to offer the decipherer less difficulties than the two others which accompanied it. The number of distinct characters employed in writing it did not exceed forty, while the words were divided from one another by a slanting wedge. Some of the words contained so many characters that it was plain that these latter must denote letters, and not syllables, and that consequently the Persian cuneiform system must have consisted of an alphabet, and not of a syllabary. It was further plain that the inscriptions had to be read from left to right, since the ends of all the lines were exactly underneath one another on the left side, whereas they terminated irregularly on the right; indeed, the last line sometimes ended at a considerable distance from the right-hand extremity of the inscription.