Only very few people of unusual will power are able to lie even in their sleep, skilfully managing the features of their faces, sometimes even preserving a courteous and bright smile on their lips, when their souls, given over to dreams, are quivering from the horrors of a monstrous nightmare--but, as exceptions, these cannot be taken into consideration.
I am profoundly happy that I am not a criminal, that my conscience is clear and calm.
"Read, my friend, read," I say to the watchful eye as I lay myself down to sleep peacefully.

"You will not be able to read anything on my face!" And it was I who invented the window in the prison door.
I feel that my reader is astonished and smiles incredulously, mentally calling me an old liar, but there are instances in which modesty is superfluous and even dangerous.

Yes, this simple and great invention belongs to me, just as Newton's system belongs to Newton, and as Kepler's laws of the revolution of the planets belong to Kepler.
Later on, encouraged by the success of my invention, I devised and introduced in our prison a series of little innovations, which were concerned only with details; thus the form of chains and locks used in our prison has been changed.
The little window in the door was my invention, and, if any one should dare deny this, I would call him a liar and a scoundrel.
I came upon this invention under the following circumstances: One day, during the roll call, a certain prisoner killed with the iron leg of his bed the Inspector who entered his cell.

Of course the rascal was hanged in the yard of our prison, and the administration light mindedly grew calm, but I was in despair--the great purpose of the prison proved to be wrong since such horrible deeds were possible.

How is it that no one had noticed that the prisoner had broken off the leg of his bed?
How is it that no one had noticed the state of agitation in which the prisoner must have been before committing the murder?
By taking up the question so directly I thus approached considerably the solution of the problem; and indeed, after two or three weeks had elapsed I arrived simply and even unexpectedly at my great discovery.
I confess frankly that before telling my discovery to the Warden of the prison I experienced moments of a certain hesitation, which was quite natural in my position of prisoner.