SINCE my report of the 3rd of this month I have continued my excavations with the greatest zeal, and although interrupted sometimes by the rain, and sometimes by Greek festivals, and also in spite of the continually increasing difficulty in removing the rubbish, I have now reached an average depth of 10 meters or about 33 English feet.[94] Much that was inexplicable to me has now become clear, and I must first of all correct an error made in my last report, that I had come upon the stone period. I was deceived by the enormous mass of stone implements of all kinds which were daily dug up, and by the absence of any trace of metal, except two copper nails, which I believed to have come in some way from one of the upper strata into the deeper stratum of the stone period. But since the 6th of this month there have appeared not only many nails, but also knives, lances, and battle-axes of copper of such elegant workmanship that they can have been made only by a civilized people. Hence I must not only recal my conjecture that I had reached the stone period, but I cannot even admit that I have reached the bronze period, for the implements and weapons which I find are too well finished. I must, moreover, draw attention to the fact, that the deeper I dig, from 7 meters (23 feet) downwards, the greater are the indications of a higher civilization. At a depth of from 4 to 7 meters (13 to 23 feet) the stone implements and weapons were of a coarse description; the knives were of flint, generally in the form of small saws, and rarely in that of a blade; but there were a very great number of sharp pieces of silex, which must likewise have served as knives. Since then, however, the stone implements, such as hammers and axes, are of much better workmanship; there still occur a quantity of silex knives in the form of saws, but they are much better made than those of the upper strata, and at a depth below 23 feet double-edged knife-blades of obsidian, which are so sharp that they might serve as razors. In these depths, moreover, as I have already said, we again meet with weapons and quantities of nails, knives, and implements of copper.