The idea at length occurred to them to impress each of these pieces with a common stamp, serving, like the trade-marks employed by certain guilds of artisans, to testify at once to their genuineness and their exact weight: in a word, they were the inventors of money. The most ancient coinage of their mint was like a flattened sphere, more or less ovoid, in form: it consisted at first of electrum, and afterwards of smelted gold, upon which parallel striae or shallow creases were made by a hammer. There were two kinds of coinage, differing considerably from each other; one consisted of the heavy stater, weighing about 14.20 grammes, perhaps of Phoenician origin, the other of the light stater, of some 10.80 grammes in weight, which doubtless served as money for the local needs of Lydia: both forms were subdivided into pieces representing respectively the third, the sixth, the twelfth, and the twenty-fourth of the value of the original. [Illustration: 056a.jpg COIN BEARING HEAD OF MOUFLON GOAT] Drawn by Faucher-Gudin, from a coin in the Cabinet des Medailles. [Illustration: 056b.jpg MONEY OF CROESUS] The stamp which came to be impressed upon the money was in relief, and varied with the banker; * when political communities began to follow the example of individuals, it also bore the name of the city where it was minted. * [The best English numismatists do not agree with M. Babelon's "banker" theory. Cf. Barclay V. Head, _Historia Nummorum_, p. xxxiv.---Tr.]