“I will, sir,” acceded the scientist.  “But first, with your permission, I’ll point out a few of its main features, and—­”

“Damn the main features!” cried Flint.  “Get busy with the demonstration!”

“Hold on, hold on,” now interrupted Waldron.  “Let him discourse, if he wants to.  Ever know a scientist who wasn’t primed to the muzzle with expositions?  Here, Herzog,” he added, turning to the inventor, “I’ll listen, if nobody else will.”

Undecided, Herzog smiled nervously.  Even Flint had to laugh at his indecision.

“All right, go on,” said the Billionaire.  “Only for God’s sake, make it brief!”

Herzog, thus adjured, cleared his throat and blinked uneasily.

“Oxygen,” he said.  “Yes, I can produce it quickly, easily and in large quantities.  As a gas, or as a liquid, which can be shipped to any desired point and there transformed into gaseous form.  Liquid air can also be produced by this same machine, for refrigerating purposes.  You understand, of course, that when liquid air evaporates, it is only the nitrogen that goes back into the atmosphere at 313 degrees below zero.  The residue is pure liquid oxygen.  In other words, this apparatus will make money as a liquid air plant, and furnish you oxygen as a by-product.

“It will also turn out nitrogen, for fertilizing purposes.  The income from a full-sized machine, on this pattern, from all three sources, should be very large indeed.”

“Good,” put in Waldron.  “And liquid air, for example, would cost how much to produce?”

“With power-cost at half a cent per H.P. hour, about $2.50 a ton.  The oxygen by-product alone will more than pay for that, in purifying and cooling buildings, or used to promote combustion in locomotives and other steam engines.  The liquid air itself can be used as a motive power for a certain type of expansion engine, or—­”

“There, there, that’s enough!” interposed Flint, brusquely.  “We don’t need any of your advice or suggestions, Herzog.  As far as the disposal of the product is concerned, we can take care of that.  All we want from you is the assurance that that product can be obtained, easily and cheaply, and in unlimited quantities.  Is that the case?”

“It is, sir.”

“All right.  And can liquid oxygen be easily transported any considerable distance?”

“Yes, sir.  In what is known as Place’s Vacuum-jacketed Insulated Container, it can be kept for weeks at a time without any appreciable loss.”

Flint pondered a moment, then asked, again: 

“Could large tanks, holding say, a million gallons, be built on that principle, for wholesale storage?  And could vacuum-jacketed pipes be laid, for conveying liquid oxygen or its gas?”

“No reason why not, sir.  Yes, I may say all that is quite feasible.”

“Very well, then,” snapped Flint.  “That’s enough for the present.  Now, show us your machine at work!  Start it Herzog.  Let’s see what you can do!”