"The road we followed was a long passage of from fifteen to twenty feet high. Its walls were very dry; and the electric light showed us a stone free from any parasitic vegetation, free even from any mouldiness. It was a sight which caused me some disquiet, for if we were to subsist for twenty days on a diet of salt ham, without any vegetable food, I feared that we might fall a prey to scurvy. My mind was at ease about the matter of drink; for I knew that in the Catacombs there were little streams of running water; and we had only to walk far enough to come across them. "M. Longuet could not reconcile himself to the idea that we were walking _without caring where we were going_. I thought it wise to make him understand the necessity of not caring where we were going. I told him, as was the truth, that during the laying of the sewer the engineers, having descended into the Catacombs through the hole, had tried in vain to find their way about them and a way out. They had had to give it up, and to content themselves with building three pillars to prop up the roof, along the top of which their sewer ran, with materials let down through the hole by which we had so hastily descended, and which had been so definitely and unfortunately bricked up over our heads. "Not to discourage him, I informed him that to my certain knowledge we could reckon on at least _three hundred and ten miles_[6] of Catacombs, and that there was no reason that there should not be more. It was evident that if I did not at once make clear to him the difficulty of getting out, he would have yielded to despair at the end of a couple of days' journey. [Footnote 6: These are the official figures.] "'Bear in mind then,' I said, 'that they hollowed this soil from the third to the seventeenth century! Yes; for fourteen hundred years man has raised from under the soil the materials which were necessary for building on the top of it! So much so that from time to time, since there is too much on the top, and in places nothing at all beneath, the things on top have returned beneath whence they came.' "Since we found ourselves under the ancient Quarter d'Enfer, I recalled to his memory that in 1777 a house in d'Enfer Street was in that way engulfed. It was precipitated a hundred and twelve feet below the pavement of its own courtyard. Some months later, in 1778, seven persons were killed in a similar landslip, in the district of Menilmontant. I quoted several examples of a later date, laying stress on the loss of life. "He understood me and said, 'In fact, it's often more dangerous to walk about on the top than underneath.' "I had gained his attention, and finding him so cheerful and interested, forgetting all about his hunger, I profited by it to quicken our steps; and I chanted the most spirited chorus I could remember. He took it up and we sang together: