Some few years ago MM. Cartailhac and Boule discovered one of these primitive quarries at Mur de Barrez, the chief town of the department of Aveyron.5 They made out eight shafts in the face of a layer of limestone some eighty-one feet long, and at every turn of their excavations they came to fresh shafts. These shafts opened out towards the top like funnels, and the), were not more than three feet three inches below the surface, the flint having been struck at that depth (Fig. 73). These shafts were, in many cases, continued by galleries, as seen in our illustration (Fig. 74), or by trenches, where the light is, however, more or less shut out by small landslips. It is still easy, in spite of this, to make out the floor of the mine, for it is trodden hard by the feet of the ancient miners. Traces of charcoal, too, reveal the path they took, and we learn at the same time that they used fire to help them in their work. [Illustration: 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. [Illustration: 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.