One would have expected to find the ground near these polishers covered with flakes of flint and pieces of tools of all kinds, but nothing of the kind has been discovered; a fact which leads its to suppose that the workmen only came down into the valley to finish off their weapons by polishing them. At the period we are considering all the continents were peopled, and we must repeat, for it is the most important point of our present study, that the civilization attained to by the inhabitants was everywhere almost identical. Thus we find centres of manufacture similar to those of Europe at the foot of the mountains of Tunis and of Algeria. In one of the latter, at Hassi al Rhatmaia, the knives were piled up in one place, the scrapers in another, and the arrow-heads in a third. In this disposition M. Rabourdin thinks he sees a sign of the division of labor, one of the most important features of modern progress. M. Arcelin mentions a similar deposit on the summit of the Jebel Kalabshee, near Esneh in Egypt, and a few years ago another was found in Palestine, near the ancient Berytus, containing great numbers of hatchets, saws, scrapers, and all the implements characteristic of the Stone age; whilst amongst them lay the blocks from which they had been cut. Asia Minor was evidently an important manufacturing centre during the Stone age, and, as a matter of course, it must have had a considerable population; and even in America discoveries of similar extent have been made. At Kinosha, in Wisconsin, Lapham made out a manufactory of flint and quartzite arrow-heads, which dates from prehistoric times, and quite recently a yet more important centre of industry has been discovered at St. Andrew (Winnipeg). The manufactories of Spiennes and Brandon deserve special notice, as they show us how our ancestors got the flint they used instead of metal. At Spiennes,2 the excavations were begun in the open air, then the chalk containing the flint was reached by the sinking of vertical shafts, many of which were as much as forty feet in depth. These shafts were connected with each other by galleries running in every direction, but always following the belts of flints. Cuttings have brought to light the very implements of the ancient miners. They were of the simplest description, such as picks made of stag-horn and heavy stone hammers, all alike bearing marks of long service.3 Similar results were obtained in England. Canon Greenwell explored near Brandon, in Suffolk, a series of 254 shafts, known in the neighborhood as Grime’s Graves. As at Spiennes, the shafts were connected by galleries from three to five feet high, and one of theta was twenty-seven feet long. The shafts and galleries had been hollowed out with the help of picks exactly like those found in Belgium; seventy-nine were picked up that had been thrown away by the workmen.4