place to put them in! A key barrel! By Jove, Brett, this looks like one of your favourite adventures. Somebody sends a key in an envelope, and a row of incomprehensible figures rolled up inside the key. Look at it!"

I took the key and the paper. The key was of a good sort; small, inscribed "Tripp's Patent" on the bow, and it evidently belonged to a superior lever lock. The paper which had come from the barrel was very thin and tough—a kind I have seen used in typewriters. It had been very carefully and closely rolled, and then pushed into the key so that its natural tendency to open out held it tightly within. Written upon it with a fine pen appeared a series of very minute figures, thus:—

"Well," inquired McCarthy, "what do you make of it?"

"Not much as yet," I admitted. "But it's pretty