I shall never forget the walk I took one night in Vienne, after having accomplished the examination of an unknown Druidical relic, the Pierre labie, at La Rondelle, near Champigni. I had learned of the existence of this cromlech only on my arrival at Champigni in the afternoon, and I had started to visit the curiosity without calculating the time it would take me to reach it and to return. Suffice it to say that I discovered the venerable pile of grey stones as the sun set, and that I expended the last lights of evening in planning and sketching.