The crimson tint, at first deep and turgid, gradually cleared, until it shone like the purest ruby. A kind of fermentation, momentarily increasing, seemed to be at work within it, and I presently noticed minute currents of blue twisting about like tiny serpents, and multiplying as they moved, until the crimson grew to violet, which, in the course of a few minutes, cleared and strengthened in its turn to a brilliant and superb purple, perfectly translucent, and emitting a lustre so powerful as partly to reveal the figure of Diana, kneeling, with her hands folded upon her lap, in an attitude of thoughtful contemplation. But the fermentation was not yet complete. Again the slender serpents twined and wreathed themselves, dispelling more and more the remaining rays of crimson, and creating a uniform and ever-intensifying light of azure. It was an azure as pure as that of an Egyptian sky, but possessing a wealth and sparkle of colour such as no atmosphere can rival--the sparkle of the ideal sapphire which no lapidary has yet discovered. 'What causes this?' I whispered at length; 'and how is it to end?' 'It is the moon purging the elixir of its last earthly impurities, and making it fit to hold its image,' replied Diana, gravely. 'These changes that you see following each other so rapidly would ordinarily last for days; it is the power given to the rays by the other lenses that hastens the work. See! the blue is already becoming green: now the green brightens into yellow: and now....' As she spoke, the fermentation gradually ceased; the liquid, having passed through all the preparatory stages, now gleamed white and pure as a diamond. The illumination which it gave forth was so intense, and yet so soft, that it permeated the whole chamber with an unearthly radiance--with the cold, colourless radiance of another world. It was as if the spirit of the moon, obeying the mandate of some irresistible spell, were present with us in that ancient tower. 'It is finished!' said Diana, with a vibration of solemnity in her tones. 'The moon is as near us now as the valley over which you saw her rise this evening. Are you ready?' Why did I hesitate? The moment for which I had so ardently wished was come. I needed but to turn my face to behold a spectacle which no human beings save Diana and her father had yet looked upon, and which, perhaps, none other than ourselves might ever see. Was it fear that withheld me? Fear of what? Of the revelation on the brink of which I stood? or of myself? 'Are you ready?' Diana repeated. 'No!' She gazed at me with eyes in which I dreaded to detect indignation or contempt. But no!--their glance was of grave and searching inquiry, nothing more. I forced myself to attempt an explanation of what I myself did not understand.