His description of the dreadful desert in the sky I looked upon, merely, as an abiding memory of the brain phantasm that had finally overthrown a reason, already tottering under the tremendous excitement induced by his discovery of the lenses, and the magnified images they had presented to him.  That there was truth in the asserted fact of the existence of these, my own experience convinced me; and curiosity as to this alone impelled me to the determination of investigating further, when my hand should be sufficiently recovered to act as no hindrance to me in forcing my way once more through the dense woods that bounded the waterfall.  Moreover, the dispassionate enquiry of a mind less sensitive to impressions might, in the result, do more towards restoring the warped imagination of my friend to its normal state than any amount of spoken scepticism.

To Camille I said nothing of my resolve; but waited on, chafing at the slow healing of my wounds.  In the meantime the period of the full moon approached, and I decided, at whatever cost, to make the venture on the evening she topped her orbit, if circumstances at the worst should prevent my doing so sooner—­and thus it turned out.

On the eve of my enterprise, the first fair spring of rain in a drought of two months fell, to my disappointment, among the hills; for I feared an increase of the torrent and the effacement of the mighty lens.  I set off, however, on the afternoon of the following day, in hot sunshine, mentally prognosticating a favourable termination to my expedition, and telling Madame Barbiere not to expect me back till late.

In leisurely fashion I made my way along the track we had previously traversed, risking no divergence through overhaste, and carefully examining all landmarks before deciding on any direction.  Thus slowly proceeding, I had the good fortune to come within sound of the cataract as the sun was sinking behind the mountain ridges to my front; and presently emerged from the woods at the very spot we had struck in our former journey together.

A chilly twilight reigned in the ravine, and the noise that came up from the ruin of the torrent seemed doubly accented by reason of it.  The sound of water moving in darkness has always conveyed to me an impression of something horrible and deadly, be it nothing of more moment than the drip and hollow tinkle of a gutter pipe.  But the crash in this echoing gorge was appalling indeed.

For some moments I stood on the brink of the slope, looking across at the great knife of the fall, with a little shiver of fear.  Then I shook myself, laughed, and without further ado took my courage in hand, and scrambled down the declivity and up again towards the cleft in the rocks.

Here the chill of heart gripped me again—­the watery sliding tunnel looked so evil in the contracting gloom.  A false step in that humid chamber, and my bones would pound and crackle on the rocks forty feet below.  It must be gone through with now, however; and, taking a long breath, I set foot in the passage under the curving downpour that seemed taut as an arched muscle.