Flamborough paused, as though to draw attention to his next point.
"I hunted about in the ditch, of course. And there, lying quite openly, was the tourniquet itself. Quite a complicated affair this time; he’s evidently improved his technique."
"Well, what about it?" Sir Clinton demanded rather testily, as though impatient of the Inspector’s comments.
"Here it is, sir."
Flamborough produced the lethal instrument with something of a flourish.
"You see, sir, it’s made out of a banjo-string threaded through a bit of rubber tubing. The handles are just bits of wood cut from a tree-branch, the same as before; but the banjo-string and the rubber tube are a vast improvement on the bit of twine he used last time, at Heatherfield. There’d be no chance of the banjo-string breaking under the strain; and the rubber tube would distribute the pressure and prevent the wire cutting into the flesh as it would have done if it had been used bare."
Sir Clinton picked up the tourniquet and examined it with obvious interest.
"H’m! I don’t say you’ve much to go on, but there’s certainly more here than there was in the other tourniquet. The banjo-string’s not much help, of course; one can buy ’em in any musical-instrument shop. But the rubber tubing might suggest something to you."
Inspector Flamborough scrutinised it afresh.
"It’s very thick-walled, sir, with a much smaller bore than one would expect from the outside diameter."
Sir Clinton nodded.
"It’s what they call ‘pressure-tubing’ in a chemical laboratory. It’s used when you’re pumping out vessels or working under reduced pressures generally. That’s why it’s made so thick-walled: so that it won’t collapse flat under the outside air-pressure when you’ve pumped all the gas out of the channel in the middle."
"I see," said the Inspector, fingering the tubing thoughtfully. "So it’s the sort of thing one finds in a scientific place like the Croft-Thornton Institute?"
"Almost certainly," Sir Clinton agreed. "But don’t get too sure about your rubber tubing. Suppose someone is trying to throw suspicion on one of the Croft-Thornton staff, wouldn’t this be an excellent way of doing it? One can buy pressure-tubing in the open market. It’s not found exclusively in scientific institutes, you know."
Flamborough seemed a shade crestfallen at the loss of what he had evidently regarded as a promising line.
"Oh, indeed?" he said. "I suppose you’re right, sir. Still it’s a bit uncommon, isn’t it?"
"Not what you’d expect the ordinary criminal to hit on straight off, I suppose you mean? But this fellow isn’t an ordinary criminal. He’s got plenty of brains. Now doesn’t it strike you as strange that he should go to the trouble of leaving this tourniquet for your inspection? He could have slipped it into his pocket easily enough and it wouldn’t have bulged much."
"Well, sir, a glance at the body would show anyone that something of the sort had been used. He wasn’t giving much away by leaving the thing itself, was he?"
Sir Clinton did not seem altogether satisfied with the Inspector’s view.
"The less a murderer leaves behind, the more difficult it is to catch him, Inspector. That’s a truism. Now this fellow is no fool, as I’ve frequently remarked to you. Hence one might have anticipated that he’d leave as few traces as possible. But here he presents us with the actual weapon, and a weapon that has fairly salient peculiarities of its own. Queer, isn’t it?"
"Then you think it’s a non-scientific murderer using scientific appliances so as to suggest that the crime was done by someone in the scientific line—Silverdale, I mean?"
Sir Clinton was silent for a moment or two, then he said thoughtfully:
"What I’m not sure about is whether it’s a pure bluff or a double bluff. It looks like one or the other."
The Inspector obviously had difficulty in interpreting this rather cryptic utterance. At last he saw his way through it.
"I think I see what you mean, sir. Suppose it’s not Silverdale that did the murder. Then somebody—knowing that this kind of tubing’s common in Silverdale’s laboratory—may have left it on purpose for us to find, so that we’d be bluffed into jumping to the conclusion—as I admit I did—that Silverdale did the trick. That would be a simple bluff. Or again, supposing it’s Silverdale who’s the murderer, then he may have left the tubing on purpose, because he’d say to himself that we’d never believe that he’d be such a fool as to chuck a thing like that down beside the body—and hence we’d pass him over in our suspicions. Is that it, sir?"
