From “Control and Surveillance“:

The original Panopticon, proposed by Jeremy Bentham, is an architectural design for a prison which has a central tower in a circular building that is divided into individual cells. Each cell extends the entire thickness of the building and has both inner and outer windows. “The occupants of the cells … are thus backlit, isolated from one another by walls and subject to scrutiny both collectively and individually by an observer in the tower who remains unseen”. The final goal is for the inmate to internalise the mechanism of surveillance that the building establishes. The actual and imagined inspections act to reinforce each other in the minds of the prisoner. As Bentham describes it, the “… apparent omnipresence of the inspector … combined with the extreme facility of his real presence”. Surveillance is continuous in its effects even if it is discontinuous in its actions.

Now compare this concept of nineteenth century to this one.