The Billionaire thus adjured, sat down and tried to calm his agitation.

“Rotten luck, eh?” he queried.  “But after all, Herzog is likely to find the book.  And even if he doesn’t, I guess we’re safe enough.  The very boldness of the plan—­supposing even that the finder could grasp it—­would put it outside the seeming range of the possible.  It’s hardly a hundred to one shot any harm may come of it.”

“All right, then, let it go at that,” said Waldron.  “And now, to business.  Suppose, for example, you’ve got a perfectly unlimited supply of oxygen-gas and liquid.  How are you going to market it?  Just what details have you worked out?”

Flint pondered a moment, before replying.  At last he said: 

“Of course you understand, Wally, I can’t give you every point.  The whole thing will be an evolution, and new ideas and processes, new uses and demands will develop as time passes.  But in the main, my idea is this:  The big producing stations will steadily extract oxygen from the atmosphere, thus leaving the air increasingly poorer and less adapted to sustaining human life.

“I shall store the oxygen in vast tanks, like the ordinary gas-tanks to be found in every city, only much bigger.  These tanks will be fed by pipe-lines from the central stations, thus.”

Flint drew toward him a sheet of his heavily embossed letter-paper, and, picking up a pencil, began to sketch a rough diagram.  Waldron, making no comment, followed every stroke with keen interest.

“From these tanks,” the Billionaire continued, “smaller pipes will convey the gaseous oxygen to every house taking our service.”

“Just like ordinary gas?”

“Precisely.  Each room will be fitted with an oxygen jet apparatus, something like a gas burner, with a safety device to prevent over supply and avoid the dangers of combustion.”

“Combustion?”

“Yes.  In pure oxygen, a glowing bit of wire will burst into flame.  Your cigar, there, would catch fire, from the merest spark in its inmost folds.  Too much oxygen in a room not only intoxicates the occupants—­we’ve already seen that effect—­but also develops a great fire risk.  So we shall have to make some provision for that, Wally.  It will be absolutely essential.”

“All right.  Allowing it’s been made, what then?” asked “Tiger,” with extraordinary interest.

“Can’t you see?  We’ll have every household under our absolute thumb?” And Flint pressed his thumb on the table to illustrate.  “My God, man, think of it!  Every city honeycombed by our pipes—­yes, and every village and hamlet too, and even every farm house that can afford it!  At first, the cost will be very low, till people have become accustomed to ozone as they are to water.  The whole ventilation problem will be solved, at once and for all time.  Where we can’t pipe in the ozone, we can use portable vaporizers, to be supplied once a month, and of sufficient capacity to keep the air of an average-sized house perfectly pure for thirty days.