As the night wore on the silence deepened. Even the chipmunks were still; and the boards of the floors and walls ceased creaking. I read on steadily till, from the gloomy shadows of the kitchen, came the hoarse sound of the clock striking nine. How loud the strokes sounded! They were like blows of a big hammer. I closed one book and opened another, feeling that I was just warming up to my work.
This, however, did not last long. I presently found that I was reading the same paragraphs over twice, simple paragraphs that did not require such effort. Then I noticed that my mind began to wander to other things, and the effort to recall my thoughts became harder with each digression. Concentration was growing momentarily more difficult. Presently I discovered that I had turned over two pages instead of one, and had not noticed my mistake until I was well down the page. This was becoming serious. What was the disturbing influence? It could not be physical fatigue. On the contrary, my mind was unusually alert, and in a more receptive condition than usual. I made a new and determined effort to read, and for a short time succeeded in giving my whole attention to my subject. But in a very few moments again
