A short descent of nineteen steps in all brings one to the floor of the theatre, at the spot appropriated to the orchestra. The stage is a low platform, approached on either hand by steps. It is deprived of some part of its original depth by pillars and barriers hardened out of that choking mud which poured down from the mountain. Such barriers present themselves on every side; they leave the theatre formless; they create gangways where none existed, walls where the spectators had clear line of vision, darkness where the sun shone freely eighteen centuries ago. In one of these gangways behind the stage the clear impression of human features looks down from the rough wet ceiling; it is the impression of a player's mask. There were doubtless many in the theatre when the seething flood rolled in. Among this darkness and these sights the sense of tragedy tightens on the imagination. The cruelty of the ruin stands before one and is not to be set aside. There are remains of frescoes here and there; but they are almost destroyed, and serve only to increase the pity that a theatre which once rang with laughter and glowed so richly with soft light and colour should lie wet, buried and forsaken in the darkness. It is sometimes said that Herculaneum was destroyed by lava--the guides use the word to this day. But Vesuvius threw out no lava in the great eruption which destroyed the cities. It ejected much in prehistoric times. Pompeii itself is built upon a lava ridge, which in the old days was quarried for millstones, thus giving rise to an important industry. But in historic times lava did not flow--if we may trust geologists--till the year 1036 A.D.