Figure 73.
Section of a flint mine; t vegetable earth, c pure limestone, c m Marly limestone, s flint.
M. Boule,[6] from whom we borrow these details, cannot restrain his astonishment at the practical knowledge shown by these prehistoric miners. He tells us that they sometimes left the flint standing as pillars at pretty short intervals, or they propped up the galleries with even more resistant material, cementing them with clay or with calcareous earth taken from the detritus. In spite of these precautions, landslips frequently occurred, and implements of stag-horn ([Fig. 75]) have often been flattened by the fall of the roof of the gallery. It is really curious to find implements of an exactly similar kind used for exactly similar purposes at Spiennes, Brandon, Mur de Barrez, and at Cissbury, to which, however, we shall have to refer again. In the shafts of Aveyron, as in those of England, the marks of blows of the picks are still to be seen, and in many cases a flint or horn-pick point is still imbedded in the rock or limestone, as if the miner had but just left his work.
Figure 74.
Plan of a gallery, half destroyed in making the excavation which revealed its existence. U gallery still visible; G′ gallery destroyed by the excavation.
In this last example of what has been done in France, we must also add that of the shafts of Nointel (Oise) and those discovered in Maine by M. de Baye, in both of which were found nodules of flint in different stages of preparation, together with some stag-horn picks. In none of these excavations was any metal implement found, or any trace of the use of metal, so that we must conclude that the mines date from Neolithic times.
We have seen how man gradually brought to perfection the tools and weapons which were at first so clumsy. The growth of industry led to the birth of commerce, or, to speak more accurately, to that of barter. From the time of the earliest migrations intercourse was begun, or rather was carried on, between the tribes, as they gradually dispersed, often travelling considerable distances from each other, and fresh proofs of these relations are continually brought to light as we become better acquainted with prehistoric times. The flints worked by the cave-men of Belgium, the fossil shells so numerous at Chaleux, in the Frontal and Nuton caves, at Thayngen on the frontier between Switzerland and Germany, in Italy, in the stations of anterior date to the terremare beds, have been found the shells of the pearl oyster of the Indian Ocean, whilst in the caves of the south of France, such as the Madeleine, that of Cro-Magnon, Bize in Hérault, and Solutré on the banks of the Saône have been picked up the shells of Arctic marine mollusca. The cave-man of Gourdan was decked with shells from the Mediterranean, and the man of Mentone in his turn wore a head-dress made of Atlantic shells. Fossil shells were also much sought after; we have alluded to those from Champagne found in Belgium; others from the shell-marl of Touraine and Anjou had been taken into the caves of Périgord, whilst sea-urchins from the cretaceous strata of the south of France were found in a prehistoric station of Auvergne, and M. Massenat picked up at Laugerie-Basse two specimens of a species not met with anywhere but in the Eocene deposits of the isle of Wight. The Neolithic station of Champigny, near Paris, has yielded some objects from the Alps, and from Belgium, from the Vosges Mountains, and the Puy de Dôme.