Dr. Thorndyke Omnibus Vol 7

by R. Austin Freeman

  Thorndyke's suggestion of "an awakening interest" on Polton's part was curiously confirmed on the following day and thereafter. For, whereas I made my perfunctory inspection of the rubbish and forthwith—literally—washed my hands of it, and even Thorndyke looked it over with little enthusiasm, Polton seemed to give it a quite extraordinary amount of attention. By degrees, he got all the mechanical oddments sorted out into classified heaps, and once I found him with a small sieve, carefully sifting the ash and dirt from the bottom of the box. And his interest was not confined to the contents of that unclean receptacle; for, having been shown the gold watch which the inspector had left with us, he skilfully prised it open and examined its interior through his eyeglass with the most intense concentration.

  Moreover, I began to notice something new and unusual in his manner and appearance: a suggestion of suppressed excitement and a something secret and conspiratorial in his bearing. I mentioned the matter to Thorndyke, but, needless to say, he had noticed it and was waiting calmly for the explanation to transpire. We both suspected that Polton had made some sort of discovery, and we both felt some surprise that he had not communicated it at once.

  And then, at last, came the disclosure; and a most astonishing one it was. It occurred a few mornings after Blandy's visit, when Thorndyke and I, happening to go up together to the laboratory, found our friend at the bench, poring over one of the heaps of mechanical fragments with a pair of watchmaker's tweezers in his hand.

  "Well, Polton," I remarked, "I should think that you have squeezed the inspector's treasures nearly dry."

  He looked up at me with his queer, crinkly smile and replied: "I am rather afraid that I have, sir."

  "And now, I suppose, you know all about it?"

  "I wouldn't say that, sir, but I know a good deal more than when I started. But I don't know all that I want to know."

  "Well," I said, "at any rate, you can tell us who set fire to that house."

  "Yes, sir," he replied, "I think I can tell you that, without being too positive."

  I stared at him in astonishment, and so did Thorndyke. For Polton was no jester, and, in any case, was much too well-mannered to let off jokes at his principals.

  "Then," said I, "tell us. Who do you say it was?"

  "I say that it was Mr. Haire," he replied with quiet conviction.

  "But, my dear Polton," I exclaimed. "Mr. Haire was in Dublin when the fire broke out, and had been there five days. You heard the inspector say that it was impossible to suspect him."

  "It isn't impossible for me," said Polton. "He could have done it quite well if he had the necessary means. And I am pretty sure that he had the means."

  "What means had he?" I demanded.

  "Well, sir," he replied, "he had an eight-day long-case clock."

  Of course, we knew that. The clock had been mentioned at the inquest. Nevertheless, Polton's simple statement impinged on me with a quite startling effect, as if some entirely new fact had emerged. Apparently it impressed Thorndyke in the same way, for he drew a stool up to the bench and sat down beside our mysterious little friend.

  "Now, Polton," said he, "there is something more than that. Tell us all about it."

  Polton crinkled nervously as he pondered the question.

  "It is rather a long and complicated story," he said, at length. "But I had better begin with the essential facts. This clock of Mr. Haire's was not quite an ordinary clock. It had a calendar movement of a very unusual kind, quite different from the simple date disc which most of these old clocks have. I know all about that movement because it happens that I invented it and fitted it to a clock; and I am practically certain that this is the very clock.

  "However, that doesn't matter for the moment, but I must tell you how I came to make it and how it worked. In those days, I was half-way through my time as apprentice, and I was doing some work for a gentleman who made philosophical instruments—his name was Parrish. Now, Mr. Parrish had a clock of this kind—what they call a 'grandfather' nowadays—and it had the usual disc date in the dial. But that was no use to him because he was rather near-sighted. What he wanted was a calendar that would show the day of the week as well as the date, and in good big characters that he could read when he was sitting at his writing-table; and he asked me if I could make one. Well, of course, there was no difficulty. The simple calendar work that is sometimes fitted to watches would have done perfectly. But he wouldn't have it because it works rather gradually. It takes a few minutes at least to make the change."

  "But," said I, "surely that is of no consequence."

  "Not the slightest, sir. The change occurs in the night when nobody can see it, and the correct date is shown in the morning. But Mr. Parrish was a rather precise, pernicketty gentleman, and he insisted that the change ought to be made in an instant at the very moment of midnight, when the date does really change. So I had to set my wits to work to see what could be done; and at last I managed to design a movement that changed instantaneously.

  "It was quite a simple affair. There was a long spindle, or arbor, on which were two drums, one having the days of the week in half-inch letters on it and the other carrying a ribbon with the thirty-one numbers painted the same size. I need not go into full details, but I must explain the action, because that is what matters in this case. There was a twenty-four hour wheel—we will call it the day-wheel—which took off from the hour-wheel, and this carried a snail which turned with it."

  "You don't mean an actual snail, I presume," said I.

  "No, sir. What clockmakers call a snail is a flat disc with the edge cut out to a spiral shape, the shape of one of those flat water-snails. Resting against the edge of the snail by means of a projecting pin was a light steel bar with two pallets on it, and there was a seven-toothed star-wheel with long, thin teeth, one of which was always resting on the pallets. I may say that the whole movement excepting the day-wheel was driven by a separate little weight, so as to save the power of the clock.

  "And now let me explain how it worked. The day-wheel, driven by the clock, made a complete turn in twenty-four hours, and it carried the snail round with it. But as the snail turned, its spiral edge gradually pushed the pallet-bar away. A tooth of the star-wheel was resting on the upper pallet; but when the snail had nearly completed its turn, it had pushed the bar so far away that the tooth slipped off the upper pallet on to the lower one—which was quite close underneath. Then the snail turned a little more and the pin came to the end of the spiral—what we call 'the step'—and slipped off, and the pallet-bar dropped back and let the tooth of the star-wheel slip off the lower pallet. Then the star-wheel began to turn until the next tooth was stopped by the upper pallet; and so it made a seventh of a turn, and, as it carried the two drums round with it, each of those made the seventh of a turn and changed the date in less than a second. Is that clear, sir?"

  "Quite clear," replied Thorndyke (speaking for himself), "so far as the mechanism goes, but not so clear as to your deductions from it. I can see that this quite innocent calendar movement could be easily converted into a fire-raising appliance. But you seem to suggest that it was actually so converted. Have you any evidence that it was?"

  "I have, sir," replied Polton. "What I have described is the calendar work just as I made it. There is no doubt about that, because when I took off the copper dial, there was the day-wheel with the snail on it still in place. Perhaps you noticed it."

  "I did, but I thought it was part of some kind of striking-work."

  "No, sir. The striking-work had been removed to make room for the calendar-work. Well, there was the day-wheel and the snail, and I have found the pallet-bar and the star-wheel and some of the other parts, so it is certain that the calendar movement was there. But there was something else. Somebody had made an addition to it, for I found another snail and another pallet-bar almost exactly like those of the calendar. But there was this difference: the day-snail had marked on it twelve lines, each denoting two hours; but this second snail had se
ven lines marked on it, and those seven lines couldn't have meant anything but seven days."

  "That is a reasonable assumption," said Thorndyke.

  "I think, sir, that it is rather more than an assumption. If you remember that the star-wheel and the spindle that carried the two drums made one complete revolution in seven days, you will see that, if this snail had been fixed on to the spindle, it would also have made a revolution in seven days. But do you see what follows from that?"

  "I don't," said I, "so you may as well explain."

  "Well, the day-snail turned once a day and, at the end of its turn, it suddenly let the pin drop into the step, released the star-wheel and changed the date in an instant. But this second snail would take a week to turn, and, at the end of the week, the pin would drop into the step, and in an instant some thing would happen. The question is, what was it that would have happened?"

  "Yes," Thorndyke agreed, "that is the question, and first, can you think of any normal and innocent purpose that the snail might have served?"

  "No, sir. I have considered that question, and I can't find any answer. It couldn't have been any thing connected with the calendar, because the weeks aren't shown on a calendar. There's no need. When Sunday comes round, you know that it is a week since last Sunday; and no one wants to number the weeks."

  "It is conceivable," I suggested, "that someone might have had some reason for keeping count of the weeks, though it does seem unlikely. But could this addition be connected with the phases of the moon? They are sometimes shown on clocks."

  "They are, usually, on these old clocks," replied Polton, "but this movement would have been of no use for that purpose. The moon doesn't jump from one phase to the next. It moves gradually; and the moon-disc on a clock shows the changes from day to day. Besides, this snail would have been unnecessary. A moon-disc could have been taken directly off the spindle and moved forward one tooth at each change of date. No, sir, I can think of no use for that snail but to do some particular thing at a given time on a given day. And that is precisely what I think it was made for."

  I could see that Thorndyke was deeply impressed by this statement, and so was I. But there were one or two difficulties, and I proceeded to point them out.

  "You speak, Polton, of doing something at a given time on a given day. But your calendar gave no choice of time. It changed on the stroke of midnight. But this fire broke out at three o'clock in the morning."

  "The calendar changed at midnight," replied Polton, "because it was set to that time. But it could have been set to any other time. The snail was not fixed immovably on the pivot. It was held fast by a set-screw, but if you loosened the screw, you could turn the snail and set it to discharge at any time you pleased."

  "And what about the other snail?" Thorndyke asked.

  "That was made in exactly the same way. It had a thick collet and a small set-screw. So you see, sir, the movement was easily controllable. Supposing you wanted it to discharge at three o'clock in the morning in five days' time; first you set the hands of the clock to three hours after midnight, then you set the day-snail so that the step was just opposite the pin, and you set the week-snail so that the pin was five marks from the step. Then both the snails would be in the correct position by the day-wheel, and at three in the morning on the fifth day both snails would discharge together and whatever you had arranged to happen at that time would happen to the moment. And you notice, sir, that until it did happen, there would be nothing unusual to be seen or heard. To a stranger in the room, there would appear to be nothing but an ordinary grand father clock with a calendar—unless the little windows for the calendar had been stopped up, as I expect they had been."

  Here Thorndyke anticipated a question that I had been about to put; for I had noticed that Polton had described the mechanism, but had not produced the parts for our inspection, excepting the carcase of the clock, which was on the bench.

  "I understand that you have the two snails and pallet-bars?"

  "Yes, sir, and I can show them to you if you wish. But I have been making a model to show how the mechanism worked, and I thought it best for the purposes of evidence, to make it with the actual parts. It isn't quite finished yet, but if you would like to see it—"

  "No," replied Thorndyke, instantly realizing, with his invariable tact and sympathy, that Polton wished to spring his creation on us complete, "we will wait until the model is finished. But to what extent does it consist of the actual parts?"

  "As far as the calendar goes, sir, almost entirely. The day-wheel was on the clock-plate where you saw it. Then I found the snail and the spindle with the star-wheel still fixed to it. That is practically the whole of it excepting the wooden drums, which, of course, have gone.

  "As to the week-mechanism, I have got the snail and the pallet-bar only. There may not have been much else, as the week-snail could have been set on the spindle and would then have turned with the star-wheel."

  "There would have had to be a second star-wheel, I suppose," Thorndyke suggested.

  "Not necessarily, sir. If it was required for only a single discharge, a pivoted lever, or something that would drop right out when the pallet released it, would do. I have found one or two wheels that might have been used, but they may have come from the gramophone motors or the projectors, so one can't be sure."

  "Then," said I, "you can't say exactly what the week-mechanism was like, or that your model will be a perfect reproduction of it?

  "No, sir," he replied, regretfully. "But I don't think that really matters. If I produce a model, made from the parts found in the ruins, that would be capable of starting a fire, that will dispose of the question of possibility."

  "Yes," said Thorndyke, "I think we must admit that. When will your model be ready for a demonstration?"

  "I can promise to have it ready by to-morrow evening," was the reply.

  "And would you be willing that Inspector Blandy should be present at the demonstration?"

  The answer was most emphatically in the affirmative; and the gratified crinkle with which the permission was given suggested keen satisfaction at the chance of giving the inspector a shock.

  So the matter was left; and Thorndyke and I retired, leaving our ingenious friend to a despairing search among the rubbish for yet further traces of the sinister mechanism.

  XVI. POLTON ASTONISHES THE INSPECTOR

  Polton's revelation gave us both a good deal of material for thought, and, naturally, thought generated discussion.

  "How does Polton's discovery impress you?" I asked. "Is it a real one, do you think, or is it possible that he has only found a mare's nest?"

  "We must wait until we have seen the model," Thorndyke replied. "But I attach great weight to his opinions for several reasons."

  "As, for instance—?"

  "Well, first there is Polton himself. He is a profound mechanician, with the true mechanician's insight and imagination. He reads a certain function into the machine which he has mentally reconstructed, and he is probably right. Then there is the matter which we were discussing recently: the puzzling, contradictory nature of the case. We agreed that the whole group of events looks abnormal; that it suggests a connected group of events, intentionally brought about, with an unlawful purpose behind it, but there is not a particle of positive evidence connecting anyone with those events in the character of agent. The crux of the matter has been from the first the impossibility of connecting Haire with the outbreak of the fire. His alibi seemed to be unchallengeable; for not only was he far away, days before the fire broke out; not only, was there no trace of any fire-raising appliance; but the presence of the other man in the rooms seemed to exclude the possibility of any such appliance having been used.

  "But if Polton's discovery turns out to be a real one, all these difficulties disappear. The impossible has become possible and even probable. It has become possible for Haire to have raised the fire while he was hundreds of miles away; and the appliance used was so ordinary in appearance tha
t it would have passed unnoticed by the man who was living in the rooms. If Polton is right, he has supplied the missing link which brings the whole case together."

  "You speak of probability," I objected. "Aren't you putting it too high? At the most, Polton can prove that the mechanism could have been used for fire-raising; but what is the evidence that it was actually so used?"

  "There is no direct evidence," Thorndyke admitted. "But consider all the circumstances. The fire, itself, looked like the work of an incendiary, and all the other facts supported that view. The fatal objection was the apparent physical impossibility of the fire having been purposely raised. But Polton's discovery—if we accept it provisionally—removes the impossibility. Here is a mechanism which could have been used to raise the fire, and for which no other use can be discovered. That, I say, establishes a probability that it was so used; and that probability would remain even if it could be proved that the mechanism had some legitimate function."

  "Perhaps you are right," said I. "At any rate, I think Blandy will agree with you. Is he coming to the demonstration?"

  "Yes. I notified him and invited him to come. I couldn't do less; and, in fact, though I have no great love for the man, I respect his abilities. He will be here punctually at eight o'clock to-night."

  In effect, the inspector was more than punctual, for he turned up, in a state of undisguised excitement, at half-past seven. I need not repeat his adulatory greeting of my colleague nor the latter's disclaimer of any merit in the matter. But I noted that he appeared to be genuinely grateful for Thorndyke's help and much more frank and open in his manner than he had usually been.

  As the demonstration had been arranged for eight, we occupied the interval by giving him a general outline of the mechanism while he fortified himself with a glass of sherry (which Thorndyke had, in some way, ascertained to be his particular weakness) and listened with intense attention. At eight o'clock, exactly, by Polton's newly-completed regulator, the creator of that incomparable time-keeper appeared and announced that the model was ready for inspection, and we all, thereupon, followed him up to the laboratory floor.