The last remark referred to the wretched Lloyd, who had fallen forward with something between a sob and a loud sigh. The policemen took him by the arms and propped him in his chair.
"System?" said Hewitt, with a shrug of the shoulders an hour or two after, in Sir James's study. "I can't say I have a system. I call it nothing but common-sense and a sharp pair of eyes. Nobody using these could help taking the right road in this case. I began at the match, just as the Scotland Yard man did, but I had the advantage of taking a line through three cases. To begin with, it was plain that that match, being left there in daylight, in Mrs. Cazenove's room, could not have been used to light the table-top, in the full glare of the window; therefore it had been used for some other purpose—what purpose I could not, at the moment, guess. Habitual thieves, you know, often have curious superstitions, and some will never take anything without leaving something behind—a pebble or a piece of coal, or something like that—in the premises they have been robbing. It seemed at first extremely likely that this was a case of that kind. The match had clearly been brought in—because when I asked for matches there were none in the stand—not even an empty box; and the room had not been disturbed. Also the match probably had not been struck there, nothing having been heard, although, of course, a mistake in this matter was just possible. This match then, it was fair to assume, had been lit somewhere else and blown out immediately—I remarked at the time that it was very little burnt. Plainly it could not have been treated thus for nothing, and the only possible object would have been to prevent it igniting accidentally. Following on this it became obvious that the match was used, for whatever purpose, not as a match, but merely as a convenient splinter of wood.
"So far so good. But on examining the match very closely I observed—as you can see for yourself—certain rather sharp indentations in the wood. They are very small, you see, and scarcely visible, except upon narrow inspection; but there they are, and their positions are regular. See—there are two on each side, each opposite the corresponding mark of the other pair. The match, in fact, would seem to have been gripped in some fairly sharp instrument, holding it at two points above, and two below—an instrument, as it may at once strike you, not unlike the beak of a bird.
"Now, here was an idea. What living creature but a bird could possibly have entered Mrs. Heath's window without a ladder—supposing no ladder to have been used—or could have got into Mrs. Armitage's window without lifting the sash higher than the eight or ten inches it was already open? Plainly, nothing. Further, it is significant that only one article was stolen at a time, although others were about. A human being could have carried any reasonable number, but a bird could only take one at a time. But why should a bird carry a match in its beak? Certainly it must have been trained to do that for a purpose, and a little consideration made that purpose pretty clear. A noisy, chattering bird would probably betray itself at once. Therefore it must be trained to keep quiet both while going for and coming away with its plunder. What readier or more probably effectual way than, while teaching it to carry without dropping, to teach it also to keep quiet while carrying? The one thing would practically cover the other.
"I thought at once, of course, of a jackdaw or a magpie—these birds' thievish reputations made the guess natural. But the marks on the match were much too wide apart to have been made by the beak of either. I conjectured, therefore, that it must be a raven. So that when we arrived near the coach-house I seized the opportunity of a little chat with your groom on the subject of dogs and pets in general, and ascertained that there was no tame raven in the place. I also, incidentally, by getting a light from the coach-house box of matches, ascertained that the match found was of the sort generally used about the establishment—the large, thick, red-topped English match. But I further found that Mr. Lloyd had a parrot which was a most intelligent pet, and had been trained into comparative quietness—for a parrot. Also, I learnt that more than once the groom had met Mr. Lloyd carrying his parrot under his coat—it having, as its owner explained, learnt the trick of opening its cage-door, and escaping.
"I said nothing, of course, to you of all this, because I had as yet nothing but a train of argument and no results. I got to Lloyd's room as soon as possible. My chief object in going there was achieved when I played with the parrot, and induced it to bite a quill tooth-pick.
"When you left me in the smoking-room I compared the quill and the match very carefully, and found that the marks corresponded exactly. After this I felt very little doubt indeed. The fact of Lloyd having met the ladies walking before dark on the day of the first robbery proved nothing, because, since it was clear that the match had not been used to procure a light, the robbery might as easily have taken place in daylight as not—must have so taken place, in fact, if my conjectures were right. That they were right I felt no doubt. There could be no other explanation.
"EXPLAINING."