The granite table, on which we had seen Benares, London and New York, was gone.

The boxes and rolls of manuscript had vanished from the cavern in which the little ex-fat man had changed lead into gold before our eyes.

The pit in the center of the cavern in which the fire-walkers had performed, still held ashes, but the ashes were cold and had either been slaked with water, or else water had been admitted into the pit from below.

At any rate, the pit was flooded, and nobody wanted the job of wading into it to look for apparatus.

So there may have been paraphernalia hidden under those ashes for aught that I know.
It was a perfectly ridiculous investigation; its findings were not worth a moment's attention of any genuine scientist.