“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.  To the reader who may still be surprised at this hesitation, knowing me to be a man of a clear, unstained conscience, I will answer by a quotation from my “Diary of a Prisoner,” relating to that period: 

“How difficult is the position of the man who is convicted, though innocent, as I am.  If he is sad, if his lips are sealed in silence, and his eyes are lowered, people say of him:  ’He is repenting; he is suffering from pangs of conscience.’

“If in the innocence of his heart he smiles brightly and kindly, the keeper thinks:  ’There, by a false and feigned smile, he wishes to hide his secret.’

“No matter what he does, he seems guilty—­such is the force of the prejudice against which it is necessary to struggle.  But I am innocent, and I shall be myself, firmly confident that my spiritual clearness will destroy the malicious magic of prejudice.”

And on the following day the Warden of the prison pressed my hand warmly, expressing his gratitude to me, and a month later little holes were made in all doors in every prison in the land, thus opening a field for wide and fruitful observation.