I sought devices to enable me mechanically to abide my waking hours.  I squared and cubed long series of numbers, and by concentration and will carried on most astonishing geometric progressions.  I even dallied with the squaring of the circle . . . until I found myself beginning to believe that that possibility could be accomplished.  Whereupon, realizing that there, too, lay madness, I forwent the squaring of the circle, although I assure you it required a considerable sacrifice on my part, for the mental exercise involved was a splendid time-killer.

By sheer visualization under my eyelids I constructed chess-boards and played both sides of long games through to checkmate.  But when I had become expert at this visualized game of memory the exercise palled on me.  Exercise it was, for there could be no real contest when the same player played both sides.  I tried, and tried vainly, to split my personality into two personalities and to pit one against the other.  But ever I remained the one player, with no planned ruse or strategy on one side that the other side did not immediately apprehend.

And time was very heavy and very long.  I played games with flies, with ordinary house-flies that oozed into solitary as did the dim gray light; and learned that they possessed a sense of play.  For instance, lying on the cell floor, I established an arbitrary and imaginary line along the wall some three feet above the floor.  When they rested on the wall above this line they were left in peace.  The instant they lighted on the wall below the line I tried to catch them.  I was careful never to hurt them, and, in time, they knew as precisely as did I where ran the imaginary line.  When they desired to play, they lighted below the line, and often for an hour at a time a single fly would engage in the sport.  When it grew tired, it would come to rest on the safe territory above.