Imagine, you who read, the nave of the vastest cathedral with which you are acquainted.  Then double or treble its size, and you will have some conception of that temple in which we found ourselves.  Perhaps in the beginning it had been a cave, who can say? but now its sheer walls, its multitudinous columns springing to the arched roof far above us, had all been worked on and fashioned by the labour of men long dead; doubtless the old fire-worshippers of thousands of years ago.

You will wonder how so great a place was lighted, but I think that never would you guess.  Thus—­by twisted columns of living flame!  I counted eighteen of them, but there may have been others.  They sprang from the floor at regular intervals along the lines of what in a cathedral would be the aisles.  Right to the roof they sprang, of even height and girth, so fierce was the force of the natural gas that drove them, and there were lost, I suppose, through chimneys bored in the thickness of the rock.  Nor did they give off smell or smoke, or in that great, cold place, any heat which could be noticed, only an intense white light like that of molten iron, and a sharp hissing noise as of a million angry snakes.

The huge temple was utterly deserted, and, save for this sybilant, pervading sound, utterly silent; an awesome, an overpowering place.

“Do these candles of yours ever go out?” asked Leo of Oros, placing his hand before his dazzled eyes.

“How can they,” replied the priest, in his smooth, matter-of-fact voice, “seeing that they rise from the eternal fire which the builders of this hall worshipped?  Thus they have burned from the beginning, and thus they will burn for ever, though, if we wish it, we can shut off their light.[*] Be pleased to follow me:  you will see greater things.”

[*] This, as I ascertained afterwards, was done by thrusting a broad stone of great thickness over the apertures through which the gas or fire rushed and thus cutting off the air.  These stones were worked to and fro by means of pulleys connected with iron rods.—­L.  H. H.

So in awed silence we followed, and, oh! how small and miserable we three human beings looked alone in that vast temple illuminated by this lightning radiance.  We reached the end of it at length, only to find that to right and left ran transepts on a like gigantic scale and lit in the same amazing fashion.  Here Oros bade us halt, and we waited a little while, till presently, from either transept arose a sound of chanting, and we perceived two white-robed processions advancing towards us from their depths.

On they came, very slowly, and we saw that the procession to the right was a company of priests, and that to the left a company of priestesses, a hundred or so of them in all.