The old man sat and talked with me for hours, and the strangest part of our intercourse was that I could read his every thought while he could not fathom an iota from my mind unless I spoke.

I did not apprise him of my ability to sense his mental operations, and thus I learned a great deal which proved of immense value to me later and which I would never have known had he suspected my strange power, for the Martians have such perfect control of their mental machinery that they are able to direct their thoughts with absolute precision.

The building in which I found myself contained the machinery which produces that artificial atmosphere which sustains life on Mars. The secret of the entire process hinges on the use of the ninth ray, one of the beautiful scintillations which I had noted emanating from the great stone in my host’s diadem.

This ray is separated from the other rays of the sun by means of finely adjusted instruments placed upon the roof of the huge building, three-quarters of which is used for reservoirs in which the ninth ray is stored. This product is then treated electrically, or rather certain proportions of refined electric vibrations are incorporated with it, and the result is then pumped to the five principal air centers of the planet where, as it is released, contact with the ether of space transforms it into atmosphere.

There is always sufficient reserve of the ninth ray stored in the great building to maintain the present Martian atmosphere for a thousand years, and the only fear, as my new friend told me, was that some accident might befall the pumping apparatus.