The lights in the lamps and along the ring and the triangles now began to pale. I resupplied their nutriment from the crystal vessel. As yet nothing strange startled my eye or my ear beyond the rim of the circle,--nothing audible, save, at a distance, the musical wheel-like click of the locusts, and, farther still, in the forest, the howl of the wild dogs, that never bark; nothing visible, but the trees and the mountain-range girding the plains silvered by the moon, and the arch of the cavern, the flush of wild blooms on its sides, and the gleam of dry bones on its floor, where the moonlight shot into the gloom. The second hour passed like the first. I had taken my stand by the side of Margrave, watching with him the process at work in the caldron, when I felt the ground slightly vibrate beneath my feet, and, looking up, it seemed as if all the plains beyond the circle were heaving like the swell of the sea, and as if in the air itself there was a perceptible tremor. I placed my hand on Margrave's shoulder and whispered, "To me earth and air seem to vibrate. Do they seem to vibrate to you?" "I know not, I care not," he answered impetuously. "The essence is bursting the shell that confined it. Here are my air and my earth! Trouble me not. Look to the circle! feed the lamps if they fail." I passed by the Veiled Woman as I walked towards a place in the ring in which the flame was waning dim; and I whispered to her the same question which I had whispered to Margrave. She looked slowly around, and answered, "So is it before the Invisible make themselves visible! Did I not bid him forbear?" Her head again drooped on her breast, and her watch was again fixed on the fire. I advanced to the circle and stooped to replenish the light where it waned. As I did so, on my arm, which stretched somewhat beyond the line of the ring, I felt a shock like that of electricity. The arm fell to my side numbed and nerveless, and from my hand dropped, but within the ring, the vessel that contained the fluid. Recovering my surprise or my stun, hastily with the other hand I caught up the vessel, but some of the scanty liquid was already spilled on the sward; and I saw with a thrill of dismay, that contrasted indeed the tranquil indifference with which I had first undertaken my charge, how small a supply was now left. I went back to Margrave, and told him of the shock, and of its consequence in the waste of the liquid. "Beware," said he, "that not a motion of the arm, not an inch of the foot, pass the verge of the ring; and if the fluid be thus unhappily stinted, reserve all that is left for the protecting circle and the twelve outer lamps! See how the Grand Work advances! how the hues in the caldron are glowing blood-red through the film on the surface!"