We were in bed by ten, for we wanted to be up and away on our tramp homeward with the dawn.  I hung fire, but Harris went to sleep at once.  I hate a man who goes to sleep at once; there is a sort of indefinable something about it which is not exactly an insult, and yet is an insolence; and one which is hard to bear, too.  I lay there fretting over this injury, and trying to go to sleep; but the harder I tried, the wider awake I grew.  I got to feeling very lonely in the dark, with no company but an undigested dinner.  My mind got a start by and by, and began to consider the beginning of every subject which has ever been thought of; but it never went further than the beginning; it was touch and go; it fled from topic to topic with a frantic speed.  At the end of an hour my head was in a perfect whirl and I was dead tired, fagged out.

The fatigue was so great that it presently began to make some head against the nervous excitement; while imagining myself wide awake, I would really doze into momentary unconsciousness, and come suddenly out of it with a physical jerk which nearly wrenched my joints apart—­the delusion of the instant being that I was tumbling backward over a precipice.  After I had fallen over eight or nine precipices and thus found out that one half of my brain had been asleep eight or nine times without the wide-awake, hard-working other half suspecting it, the periodical unconsciousnesses began to extend their spell gradually over more of my brain-territory, and at last I sank into a drowse which grew deeper and deeper and was doubtless just on the very point of being a solid, blessed dreamless stupor, when—­what was that?

My dulled faculties dragged themselves partly back to life and took a receptive attitude.  Now out of an immense, a limitless distance, came a something which grew and grew, and approached, and presently was recognizable as a sound —­it had rather seemed to be a feeling, before.  This sound was a mile away, now—­perhaps it was the murmur of a storm; and now it was nearer—­not a quarter of a mile away; was it the muffled rasping and grinding of distant machinery?  No, it came still nearer; was it the measured tramp of a marching troop?  But it came nearer still, and still nearer—­and at last it was right in the room:  it was merely a mouse gnawing the woodwork.  So I had held my breath all that time for such a trifle.

Well, what was done could not be helped; I would go to sleep at once and make up the lost time.  That was a thoughtless thought.  Without intending it—­hardly knowing it—­I fell to listening intently to that sound, and even unconsciously counting the strokes of the mouse’s nutmeg-grater.  Presently I was deriving exquisite suffering from this employment, yet maybe I could have endured it if the mouse had attended steadily to his work; but he did not do that; he stopped every now and then, and I suffered more while waiting and listening for him to begin again than I did while he was gnawing.