“The inventor, who lives at Cologne, was over here three months ago, and claimed for it that it lasted out three tyres of any of the present well-known makes,” I replied. “But, as a matter of fact, I must admit that I’ve never tried it myself.”

“You’ve sold some, of course?”

“Yes, several sets—and I believe they’ve given satisfaction.”

“You are, I take it, the only agent in this country?”

“No; Farmer and Payne, in Glasgow, have the agency for Scotland,” I replied, greatly wondering why this tyre should attract him if he had no personal interest in cars.

A second time he examined the cover, again very closely; then, placing it aside, he thanked me, apologising for taking up my time.

“Mind,” he said, “not a word to a soul that you have shown me this.”

“I have promised, Mr Kirk, to say nothing,” I said; “but your injunctions as to secrecy have, I must confess, somewhat aroused my curiosity.”

“Probably so.” And a good-humoured smile overspread his thin, rather melancholy face. “But our acquaintance is not very intimate, is it? I’ve often been on the point of asking you to run in and have a smoke with me. I’m a trifle lonely, and would be so delighted if you’d spend an hour with me.”

My natural curiosity to discover more about this man, who was such a mystery, prompted me to express a mutual desire for a chat.