The manufacture of implements of flint and obsidian had reached a high pitch of perfection during the early days of metal, and although the new materials were valuable for ornaments, copper knives were, in many respects, less serviceable than stone ones, as the metal is soft and its edge easily turned. It is true that many men, particularly those who wished to display their wealth, preferred copper daggers to those made of flint, for they were more ornate, more novel and had a scarcity value. Those, however, who were poor, or untouched by the fashionable snobbery, preferred the well-tried flint article, which was probably more effective for its purpose. But with the discovery that the addition of about ten per cent. of tin to the copper produced an alloy of considerable hardness and no little toughness as well, from which could be made implements which seldom chipped or turned, and which could have their edges quickly renewed by hammering or grinding did such an accident happen, the days of copper came quickly to an end, and the traffic in flint implements, even in obsidian, fell upon evil days. It was this discovery, which made metal not merely a luxury, but a really serviceable article to man, which brought the stone age to an end and ushered in the true metal age. How, when and where this discovery was made is still a mystery. At one time I was disposed to think that it was perhaps in Spain, where both these metals are found, that the discovery was accidentally made, but evidence which has come to hand quite recently has disposed of this idea. Professor Sayce has recently published an extract from a tablet found in the royal library of Assur.[99] It is from a document drawn up in the reign of Sargon of Akkad, whose date has now been finally fixed at 2800 /B.C./ It is a geographical description of that monarch’s empire, giving a list of the provinces, at the close of which it is said that his conquests had extended “from the lands of the setting sun to the lands of the rising sun, namely to the tinland (Ku-Ki) and Kaptara (Crete) countries beyond the Upper Sea (the Mediterranean).” At first there was a tendency to interpret this passage as though Ku-Ki was beyond the Mediterranean, and must refer either to Spain or Brittany; but this is to misunderstand the passage. As Professor Sayce says: “the western extension of the empire ended with the Syrian coast; beyond that were Kaptara or Krete and the Tinland.” Ku-Ki may well have been Cyprus, or some other island in the Mediterranean, or some region easily accessible from it.