I looked at it closely. As nearly as I could make out, there seemed to be a slight agitation on the surface of the thin film of water in the gla.s.s. Craig smiled quietly to himself and flicked the water into the sink, returning the crystal to his watch.

I did not understand just what it was that Craig was after, but I felt sure that there was some kind of vibration that he had discovered.

Meanwhile, we could hear Creighton telephoning and I noticed that Miss Laidlaw was alertly listening, too.

"Why, no," I heard him answer monosyllabically but in a tone that was carefully modulated, "not alone. Let me call you up--soon."

The conversation ended almost as abruptly as it had begun. Somehow, it seemed evident to me that Creighton had been talking to a woman. Though he apparently had not wanted to say anything before us, he could not disguise the fact. From his quick, nervous manner with us, I had concluded that no mere man could have commanded so deferential a tone from him.

A moment later he rejoined us, resuming his praises of his motor. By this time I had come to recognize that he was a master in the manipulation of fantastic terms, which I, at least, did not understand.

Therein, perhaps, lay their potency, though I doubt whether Kennedy himself knew what Creighton meant when he talked of "polar sympathy,"

"inter-atomic ether," "molecular disintegration," and "orbitic chaos."

I saw that Adele Laidlaw was watching Creighton narrowly now. Was it on account of the telephone call? Who had it been? Perhaps, it occurred to me, it was Mrs. Barry. Was Creighton afraid of arousing the jealousy of Adele Laidlaw?

There seemed to be nothing more of importance that Craig could learn at present and we soon bade Creighton good-by, leaving with Miss Laidlaw. I noticed that he locked the door after us as we went out.

"I'd like to meet this Mrs. Barry," remarked Craig as we pa.s.sed out of the building.

He said it evidently to see just how Miss Laidlaw would take it. "I think I can arrange that," replied Adele Laidlaw colorlessly. "I'll ask her to visit me this afternoon. You can call casually."

We accompanied her to her car, promising to report as soon as possible if we discovered anything new.

"I'm going in to call on Tresham," remarked Craig, turning into the Bank Building.

CHAPTER XXVI

THE ELECTROLYSIS CLEW

As Kennedy walked through the corridor of the building, he paused and bent down, as though examining the wall. I looked, too. There was a crack in the concrete, in the side wall toward the Creighton laboratory.

"Do you suppose vibration caused it?" I asked, remembering his watch crystal test.

Craig shook his head. "The vibrations in a building can be shown by a watch gla.s.s full of water. You saw the surface of the liquid with its minute waves. There's vibration, all right, but that is not the cause of such cracks as these."

He stood for a moment regarding the crack attentively. On the floor on which we were was the Consolidated Bank itself. Beneath us were the Consolidated Safety Deposit vaults.

"What did cause them, then?" I asked, mystified.

"Apparently escaping currents of electricity are causing electrolysis of the Bank Building," he replied, his face wrinkled in thought.

"Electrolysis?" I repeated mechanically.

"Yes. I suppose you know how stray or vagrant currents affect steel and concrete?"

I shook my head in the negative.

"Well," he explained as we stood there, "I believe that in one government test at least it was shown that when an electric current of high voltage pa.s.ses from steel to concrete, the latter is cracked and broken. Often a mechanical pressure as great as four or five thousand pounds a square inch is exerted and there is rapid destruction due to the heating effect of the current."

I expressed my surprise at what he had discovered. "The danger is easily overestimated," he hastened to add. "But in this case I think it is real, though probably it is a special and extreme condition. Still it is special and extreme conditions which we are in the habit of encountering in our cases, Walter. That is what we must be looking out for. In this instance the destruction due to electrolysis is most likely caused by the oxidation of the iron anode. The oxides which are formed are twice as great in volume as the iron was originally and the resulting pressure is what causes the concrete to break. I think we shall find that this condition will bear strict watching."

For a moment Kennedy stopped at the little office of the superintendent of the building, in the rear.

"I was just wondering whether you had noticed those cracks in the walls down the corridor," remarked Kennedy after a brief introduction.

The superintendent looked at him suspiciously. Evidently he feared we had some ulterior motive, perhaps represented some rival building and might try to scare away his tenants.

"Oh, that's nothing," he said confidently. "Just the building settling a bit--easily fixed."

"The safety vault company haven't complained?" persisted Kennedy, determined to get something out of the agent.

"No indeed," he returned confidently. "I guess they've got troubles of their own--real ones."

"How's that?" asked Craig, falling in with the man's evident desire to change the subject.

"Why, I believe their alarm system's out of order," he replied. "Some of the fine wires in it burnt out, I think. Defective wiring, I guess. Oh, they've had it patched up, changed about a little,--it's all right now, they say. But they've had a deuce of a time with the alarm ringing at all sorts of hours, and not a trace of trouble."

I looked quickly at Craig. Though the superintendent thought he had been very clever in changing the topic of conversation, he had unwittingly furnished us with another clew. I could not ask Craig before him and I forgot to do so later, but, to me at least, it seemed as if this might be due to induction from the stray currents.

"No one here seems to have suspected the Creighton motor, anyhow,"

commented Craig to me, as we thanked the superintendent and walked across to the elevators.

We rode up to Tresham's office, which was on the third floor, on the side of the building toward Creighton's laboratory. In fact one of the windows opened almost on the roof of the brick building next door.

We found Tresham in his office and he received us affably, I thought.

"Miss Laidlaw told me she was going to consult you," he remarked as we introduced ourselves. "I'm glad she did so."

Tresham was a large, well-built fellow, apparently athletically inclined, clean shaven with dark hair that was getting very thin. He seemed quite at ease as he talked with us, yet I could tell that he was weighing us all the time, as lawyers will do.

"What do you think of Creighton's motor?" opened Kennedy. "You've seen it, I suppose?"

"Oh, yes," he replied quickly and jerkily. "Since Miss Laidlaw became interested he's been in here to have me look over his application for a patent. You know, I used to be a patent lawyer for a number of years until I decided to branch out into general practice. Legally Creighton seems to be sound enough. Of course, you know, the patent office won't grant a patent on a machine such as he claims without a rigid demonstration. He needs money, he says, for that. If his idea is sound, I don't see any reason why he shouldn't get a basic patent."

Tresham paused. I was conscious that he was furtively watching the face of Kennedy as though he hoped to learn as much from him as Craig did on his part.

"It's the mechanical end of it that I don't understand," continued Tresham, after a pause. "Creighton claims to have discovered a new force which he calls vibrodyne. I think it is just as well that Miss Laidlaw has decided to consult a scientist about it before she puts any more money into the thing. I can't say I approve of her interest in it--though, of course, I know next to nothing about it, except from the legal standpoint."

"Who is that Mrs. Barry of whom Miss Laidlaw spoke?" asked Kennedy a moment later.

"I believe she is a friend of Creighton's. Somehow she got acquainted with Miss Laidlaw and introduced her to him."

"You know her?" queried Craig casually.

"Oh, yes," came the frank reply. "She has been in to see me, too; first to interest me in the motor, and then to consult me about various legal points in connection with it."