Just as the modern Stone races passed straight from the Stone Age into the most highly-developed Iron Age of the most advanced culture, so also the stone stratum of Central and South Africa is immediately overlaid by a stratum of iron culture, which was brought there in ancient times, probably direct from Egypt. As there is in Egypt and throughout North Africa a regular development from the Copper-bronze Period to the complete iron culture, corresponding to the progress of the metal cultures of Europe and Asia, the point of time is thus chronologically fixed at which this important element of culture was transmitted from Europe to the blacks of Central and South Africa. [Illustration: WEAPONS USED BY MAN IN THE PERIODS OF DAWNING HISTORY Reproduced chiefly from specimens in the British Museum. ] [Sidenote: Advancing Civilisation in Bronze Age] In Western Switzerland the transition period of copper is followed without a gap in the development by the Bronze Period proper. With the introduction of bronze all the conditions of life were more highly developed in the sense of increased culture. With better tools the stations of the Bronze Age could be erected at a greater distance from the bank, often two hundred to three hundred yards; the space they take up is also much greater. The piles are not only better preserved, according as the time of their being driven in more nearly approaches our own, but they are also better worked, are often square, and the points that are rammed into the lake-bottom are better cut. The settlements of the Bronze Age often cover an area of several hundred square yards, and are no longer comparatively mean villages, as in the Stone Age; the pile settlements of the Bronze Age are well-organised market towns and even flourishing small cities, where a certain luxury already prevails. The products of their industry are graced by that beauty and elegance of form that only an advanced civilisation can create. As in the Stone Age, so also in the Bronze Age of Central and Northern Europe, the most important working-implement, which was, however, also used as a weapon, was the axe, or celt. The most primitive forms of axes, like the above-mentioned copper axes, still resemble the simple stone axes: like these, they have no special contrivance for fastening the handle. In more developed forms of axes such contrivances for fastening the handle appear first in the form of slight flanges, which become wider and wider; finally they develop into regular wings, which, by curving towards one another, develop into two almost closed lateral semi-canals on the upper side of the celt. In the hollow celts a simple socket for the handle was cast in the making; an additional means of fastening the handle was provided in a loop, which also occurs on winged celts. Besides the celt, or axe-blade, broad and narrow chisels of bronze occur in various forms for working wood.