"Oh, there are a lot of 'em," he answered again, half evasively. "There's sound-ranging, of course. Then there's the hydrophone. And as a matter of fact the best brains in the world to-day are trying to cut-out sound—aeroplane propellers and so on.... What I mean is Esdaile's not hearing anything. I suppose it's just possible that he didn't. All a matter of where the sound-wave hits. You remember the broken windows in the Strand when Fritz used to come over and drop his eggs? First a broken one, then two or three whole ones, then broken ones again, all along the street? Well, this might have been one of those dumb intervals. Otherwise he must have heard. And I should have thought he'd have felt the vibration too."
"He's admitted he thought he heard something."
"Pooh, there was no mistaking it. If he didn't recognize it we can take it he didn't hear it. If we believe him, of course."
"Don't you believe him?"
"Yes," Hubbard answered without a moment's hesitation.
"Then——?"
"Oh, I suppose it means I'm on the wrong track," Hubbard replied.
Naturally any track of that nature was totally unexplored by me; but I was far from dismissing it on that account. Here again my ignorance of modern War came in to humble me. For what is the good of saying things are fantastic and far-fetched—sound-ranging and the selenium cell and what not—when for a number of years the food we have eaten and the clothes we have worn and the roofs over our heads have depended on just such fantasies? Not for nothing were those clusters of listening cones at Hyde Park Corner and on Parliament Hill, not for nothing those wireless masts over our heads at that very moment. Their operation might be unfamiliar to me, but these things were the daily business of Commander Hubbard, R.N. He turned as naturally to them as I myself turn to those equally mysterious things, a man's motives and the operative emotions of his heart.
"For all that," said Hubbard abruptly, "I should like to have a good look at that cellar of his."
I was silent. I didn't know whether his wish to see the cellar included sound-experiments on the roof also.