This time it was really a curious pattern; something like the spokes of a wheel, all meeting at a common centre, and this centre formed by a device which looked like a bowl; all, you understand done in flints."

"You are right," said Dyson, "that seems odd enough. Still it is reasonable that your half-a-dozen school children are responsible for these fantasies in stone."

"Well, I thought I would set the matter at rest. The children pass the gate every evening at half-past five, and I walked by at six, and found the device just as I had left it in the morning. The next day I was up and about at a quarter to seven, and I found the whole thing had been changed. There was a pyramid outlined in flints upon the grass. The children I saw going by an hour and a half later, and they ran past the spot without glancing to right or left. In the evening I watched them going home, and this morning when I got to the gate at six o'clock there was a thing like a half moon waiting for me."

"So then the series runs thus: firstly ordered lines, then, the device of the spokes and the bowl, then the pyramid, and finally, this morning, the half moon. That is the order, isn't it?"

"Yes; that is right. But do you know it has made me feel very uneasy? I suppose it seems absurd, but I can't help thinking that some kind of signalling is going on under my nose, and that sort of thing is disquieting."

"But what have you to dread? You have no enemies?"

"No; but I have some very valuable old plate."

"You are thinking of burglars then?" said Dyson, with an accent of considerable interest, "but you must know your neighbours. Are there any suspicious characters about?"

"Not that I am aware of. But you remember what I told you of the sailors."

"Can you trust your servants?"

"Oh, perfectly. The plate is preserved in a strong room; the butler, an old family servant, alone knows where the key is kept. There is nothing wrong there. Still, everybody is aware that I have a lot of old silver, and all country folks are given to gossip. In that way information may have got abroad in very undesirable quarters."

"Yes, but I confess there seems something a little unsatisfactory in the burglar theory. Who is signalling to whom? I cannot see my way to accepting such an explanation. What put the plate into your head in connection with these flints signs, or whatever one may call them?"

"It was the figure of the Bowl," said Vaughan. "I happen to possess a very large and very valuable Charles II punch-bowl. The chasing is really exquisite, and the thing is worth a lot of money. The sign I described to you was exactly the same shape as my punch-bowl."

"A queer coincidence certainly. But the other figures or devices: you have nothing shaped like a pyramid?"

"Ah, you will think that queerer. As it happens, this punch-bowl of mine, together with a set of rare old ladles, is kept in a mahogany chest of a pyramidal shape. The four sides slope upwards, the narrow towards the top."

"I confess all this interests me a good deal," said Dyson. "let us go on then. What about the other figures; how about the Army, as we may call the first sign, and the Crescent or Half moon?"

"Ah, there is no reference that I can make out of these two. Still, you see I have some excuse for curiosity at all events. I should be very vexed to lose any of the old plate; nearly all the pieces have been in the family for generations. And I cannot get it out of my head that some scoundrels mean to rob me, and are communicating with one another every night."

"Frankly," said Dyson, "I can make nothing of it; I am as much in the dark as yourself. Your theory seems certainly the only possible explanation, and yet the difficulties are immense."

He leaned back in his chair, and the two men faced each other, frowning, and perplexed by so bizarre a problem.

"By the way," said Dyson, after a long pause, "what is your geological formation down there?"

Mr. Vaughan looked up, a good deal surprised by the question.

"Old red sandstone and limestone, I believe," he said. "We are just beyond the coal measures, you know."

"But surely there are no flints either in the sandstone or the limestone?"

"No, I never see any flints in the fields. I confess that did strike me as a little curious."

"I should think so! It is very important. By the way, what size were the flints used in making these devices?"

"I happen to have brought one with me; I took it this morning."

"From the Half moon?"

"Exactly.