Now, it seems that a talking animal is the greatest possible joke known to the blacks, and so my narrative was greeted with uproarious mirth; and my "impossible" story even spread from tribe to tribe.

I found it was no use telling the blacks anything they could not readily comprehend.
One day I told them about the destruction of Sodom and Gomorrah by fire and brimstone, and this again landed me in disaster, for I was promptly asked how could any one, Great Spirit or other, burn up _the stones_ of which the houses were composed?
And, of course, each instance of this kind would be pounced upon by a tribal medicine-man or some other jealous enemy, and used to discredit me.

A few days after telling the Sodom and Gomorrah story, I was on a walk-about with Yamba in my mountain region, when I suddenly discovered that shale existed in very considerable quantities, and I thereupon conceived the idea of demonstrating to the blacks that, not only was the Bible narrative a true one, but that it was quite possible to ignite stone; _and I would even show them how it was done_! Aided by Yamba and other members of my family, I constructed an immense shaft-like cairn, mainly composed of loose pieces of shale intermixed with sandstone.

I put in the sandstone and other stones, partly in order that the blacks might not notice the uniform construction of the cairn; and partly also because I knew that when the ordinary stones were heated, they would probably burst or explode with a loud sound, and so terrify the superstitious onlookers.

The cairn was about fifteen feet high, with an opening at the summit and other small openings at the sides in order to ensure a good draught.