"In 1880 I succeeded a Mr. Q. as librarian of the X. Library. I had never seen Mr. Q., nor any photograph or likeness of him, when the following incidents occurred. I may, of course, have heard the library assistants describe his appearance, though I have no recollection of this. I was sitting alone in the library one evening late in March 1884, finishing some work after hours, when it suddenly occurred to me that I should miss the last train to H., where I was then living, if I did not make haste. It was then 10.55, and the last train left X. at 11.5. I gathered up some books in one hand, took the lamp in the other, and prepared to leave the librarian's room, which communicated by a passage with the main room of the library. As my lamp illumined this passage, I saw apparently at the further end of it a man's face. I instantly thought a thief had got into the library. This was by no means impossible, and the probability of it had occurred to me before. I turned back into my room, put down the books, and took a revolver from the safe, and, holding the lamp cautiously behind me, I made my way along the passage--which had a corner, behind which I thought my thief might be lying in wait--into the main room. Here I saw no one, but the room was large and encumbered with bookcases. I called out loudly to the intruder to show himself several times, more with the hope of attracting a passing policeman than of drawing the intruder. Then I saw a face looking round one of the bookcases. I say looking _round_, but it had an odd appearance as if the _body_ were _in_ the bookcase, as the face came so closely to the edge and I could see no body. The face was pallid and hairless, and the orbits of the eyes were very deep. I advanced towards it, and as I did so I saw an old man with high shoulders seem to _rotate_ out of the end of the bookcase, and with his back towards me and with a shuffling gait walk rather quickly from the bookcase to the door of a small lavatory, which opened from the library and had no other access. I heard no noise. I followed the man at once into the lavatory; and to my extreme surprise found no one there. I examined the window (about 14 in. x 12 in.), and found it closed and fastened. I opened it and looked out. It opened into a well, the bottom of which, 10 feet below, was a sky-light, and the top open to the sky some 20 feet above. It was in the middle of the building, and no one could have dropped into it without smashing the glass nor climbed out of it without a ladder--but no one was there. Nor had there been anything like time for a man to get out of the window, as I followed the intruder instantly. Completely mystified, I even looked into the little cupboard under the fixed basin. There was nowhere hiding for a child, and