Three weeks passed before we made any further progress. A clue, but always an imaginary clue, would prick us into feverish activity, which invariably led us nowhere.

But toward the end of the third week of our search, St. Hilary came to my rooms one afternoon, triumphant. He had actually made a discovery. And this discovery proved, beyond the peradventure of a doubt, not only that the clock had a story to tell, not only that the twelve hours actually did constitute twelve links of a chain, but that somewhere, in the background of each hour, there was some mark corresponding to a like mark in some part of Venice.

“It is only a little clue,” he said with affected modesty, “a very little one. But who knows that it may not be the wedge that shall pry open our treasure-box?”

“Produce this wedge by all means,” I said skeptically.

“This morning, about half past ten, I found myself in the Campo San Salvatore–you know it, the little square with the house of the gaily painted balcony and the roses on the north side. At the left of the square, going toward San Marco, perhaps you remember, there is a boys’ school. You may have observed a respectable old servant who walks solemnly up to the big bell on the left of the door, leading a little boy by the hand. He always rings the bell at eight o’clock in the morning. When the door is opened he hands the school-books to his charge, shakes his finger at him, and toddles off to the seller of sweetened water at the corner for a drink.”

“Has this respectable old man anything to do with your precious discovery?” I asked impatiently.

“A great deal to do with it. This morning, as I was saying, I caught sight of my old man and the young gentleman. My eyes dwelt on them affectionately while the servant rang the big bell, and shook his forefinger at the smiling boy. Now observe, my dear Hume; if I hadn’t met my old man, I should have hurried through the square. In that case I should have missed the boy with the fish.”

“Oh, there is a boy with a fish, is there?” I remarked.

“Yes,” he said severely, “there is a boy with a fish. While I stood watching the old man, a stream of curses and abuse in the Venetian dialect disturbed my pleasant reflections. I turned, and there, at the open door of a large house, stood a barefooted boy with a flat basket of fish. Two servants were shrieking at him like the very devil. The fish was bad, perhaps, or the boy had given the wrong change. I do not know. The point is that the old servant, the seller of sweetened water, who left his stand, and the dark-eyed gipsies at the well, who left their buckets, came to look on. The bad little boy with the fish didn’t like this publicity. Especially when a majestic policeman with a long feather in his round hat––”

I groaned. “Is the majestic policeman with the long feather in his round hat absolutely essential?”

“The majestic policeman with the long feather in his round hat is absolutely essential”, said St. Hilary with an amused drawl.

“Even the long feather in the round hat!” I could not resist asking.

“Especially the long feather in the round hat, as you will see if you are patient For this majestic policeman came on the bad little boy quite unawares, and, seizing his ear, he made him a prisoner. Then the youngster wrenched himself free, only to run headlong into another policeman who was coming from the Calle San Rosario. The spighetti, compelled to double on his tracks, plunged recklessly into the first opening that offered. This happened to be the gate leading into the school garden, that chanced to be wide open. Now, we thought, the youngster will surely be caught, and when the policeman with the long feather in his hat languidly strolled after his prey, the rest of the square pressed respectfully after to see the fun. But the young ragamuffin had the policeman now quite at his mercy, for he lost himself immediately among threescore of boys at play. So that presently, while the policeman was vainly searching the garden for him, the bad little boy regained the entrance. He cast one cautious eye into the square to be sure that the second policeman had disappeared, and then, after the manner of small boys the world over, he held his thumb and fingers extended at the majestic policeman, and called him naughty names.”

“A beautiful little sketch of low life in Venice,” I said sarcastically. “But I fail to see even yet the pertinency of the long feather in the round hat.”

“Patience, my friend. When he had sufficiently insulted the majestic policeman in this manner, he took one of his mullets, and hurling it with precision–-–”

“Struck the round hat with the long feather.”

“–Missed the round hat with the long feather,” corrected St. Hilary with calm precision, “but struck the long feather on the round hat. It hung pitifully, a draggled and wobegone bit of finery; and those of us who had followed him into the court naturally regarded it with respectful sympathy. And then my heart came into my mouth. The broken feather was pointing, as it were a human hand, straight to a round––”

“Not another round hat!” I cried in despair.

“–Straight to a round stone let into the wall. And on this round stone was carved a camel’s head, the precise image of the camel’s head in this photograph of the background of the fourth hour.”

St. Hilary looked at me in triumph, and, picking up the photograph, thrust it into my hand.

“The precise image of the camel’s head in this photograph,” I repeated, trying to grasp the significance of that statement. “But why should you think that the clock-maker copied the head of that particular camel in the background of the fourth hour? My dear St. Hilary, your introduction was too elaborate for your news to be striking. I expected something more startling.”

“But, idiot,” cried the dealer, exasperated, “look at the photograph. Do you see nothing peculiar about that camel’s head?”

I took the magnifying-glass and studied the photograph carefully.

“Nothing–unless it be the eye. Perhaps it is a defect in the workmanship. But it looks–yes, it certainly does look as if the camel was blind.”

“The camel carved on the stone let into the wall of the house is blind also.”

“This is news, if it is not the merest chance,” I cried.

“And before the house was used as a school, it was called the House of the Blind Camel.”

“The House of the Blind Camel!” I repeated excitedly. “By Jove, St. Hilary, does that mean you have stumbled on one of the twelve landmarks?”

“Patience. Look at your photograph again. What else do you see in the background of the fourth hour?”

“A well,” I answered promptly. “If you have found the well, there can be no doubt.”

“And I have found the well. Look at the photograph. What is the design of the beading round the curb?”

“A looped wreath with pomegranates between each loop.”

“The well in the school garden has a beading of the same design. But study the photograph a moment–look carefully at the second and third pomegranates from the left. Do you notice anything peculiar?”

“No, I see nothing peculiar about them.”

“The more we study the history of this clock, Hume, the more I am impressed with the fact that the eye is a most unreliable organ. We rarely see a thing as it actually is; we see it as we expect it to be. Take the magnifying-glass and look at those second and third pomegranates carefully.”

“I see now,” I cried. “They are not pomegranates; they are two rosettes.”

“And there are two rosettes between two of the loops of the well in the garden. You grasp the importance of the discovery, I hope. It means that we have to study the photographs from quite a different point of view. All we have to do now is to find in the various backgrounds some significant mark that is paralleled in the various landmarks about Venice that lead to the casket.”

“Are you not a little too sanguine, St. Hilary? These twelve marks are often most obscure. In the fifth and the eleventh hours there are no marks whatever.”

“That is true,” replied St. Hilary thoughtfully. “This discovery by itself is quite useless. If we could have found the mark of the fifth hour we could have begun at this fourth hour. But since that is missing––”

“And I suppose it is useless for us to think of beginning with the landmarks of the last hours, even if we could find them in the background. The last of the landmarks would be almost certainly found not in the open air, but in the interior of some palace.”

“There is another difficulty that has just occurred to me,” continued St. Hilary. “We have been taking it for granted that we start from the Pillar of San Marco in the Piazzetta. I still think that it is reasonable that the search begins there. If that be true, we find ourselves in the fourth hour at the Campo San Salvatore, but the landmark of the sixth hour brings us back to the balcony of San Marco in the Piazza again. In the next hour we simply stroll a few feet away to the Campanile. In that case the mad clock-maker has been leading us about in a senseless circle. He may have been mad, but he was not as mad as that.”

“Then you think the wisest thing is for us to search for the second landmark? It does not seem particularly promising. So far as I can see, it is merely a curtain, with a conventional decoration of what appears to be more like two husks of corn than anything else I can think of. One of these husks is perpendicular; the other horizontal.”

“I see no reason why we should not begin with the sixth hour,” asserted St. Hilary.

“I think we may begin at any one of them with an equal chance of success,” I said hopelessly. “This search of ours is like nothing so much as hunting for twelve needles in twenty thousand haystacks.”

And it turned out that I was right. For several days we made no farther progress. We became so utterly fatigued and weary of looking for we knew not what that we saw nothing. We took to wandering vaguely about the canals and the streets. A restlessness urged us out at all hours in search of these vague landmarks. Every morning after breakfast we set out somewhere. Every evening we returned discouraged. And so a month passed, and we were no nearer to the da Sestos casket.