You push the revolving door and you are inside and outside at the same time. The revolving door is the only door that does not open and does not close. The revolving door revolves. The revolving is the genius because the revolving means the building is never open to the weather and the never open to the weather means the heat stays in during the winter and the cool stays in during the summer and the staying in is the energy savings and the energy savings is why every office building in every cold city has a revolving door. The revolving door is the most efficient entrance ever invented and the efficiency is invisible because you are too busy pushing to notice.

Theophilus Van Kannel patented the revolving door in eighteen eighty eight in Philadelphia and the patent said the purpose was to prevent the annoyance of holding doors open for other people. Van Kannel did not want to hold the door. Van Kannel wanted to walk through the door without social obligation and the without social obligation is the most American invention since the automobile. The revolving door eliminates courtesy. The revolving door eliminates the after you and the no after you and the awkward dance of two people arriving at a door at the same time. The revolving door says everyone goes through at their own speed and the own speed is the democracy and the democracy is mechanical.

The revolving door at the Savoy Hotel in London has been spinning since nineteen oh four and the spinning is the hotel's first impression. You push through the door and the brass gleams and the glass reflects your face back at you and the reflection is the hotel telling you that you look good enough to be here. The Savoy's revolving door has admitted kings and criminals and rock stars and the door did not distinguish between them because the revolving door does not judge. The revolving door admits everyone who pushes and the pushing is the only qualification and the qualification is democratic even in the least democratic hotel in London.

The revolving door traps people. Everyone has been trapped in a revolving door. You push and someone else pushes from the other side and the door stops and you are in the compartment and the compartment is a glass cage and the glass cage is the most embarrassing place in any building. You stand in the stopped revolving door and you can see the lobby and you can see the street and you are in neither and the neither is the purgatory. The revolving door that traps you is the revolving door teaching you that the entrance is not guaranteed. The entrance requires timing and the timing requires awareness and the awareness is the price of admission.

You watch the revolving door from across the lobby and the door spins and people appear and disappear and the appearing and disappearing is the magic trick the building performs all day. The revolving door is a machine that turns outside people into inside people. The transformation takes three seconds. Three seconds ago you were on the sidewalk with the wind and the noise. Now you are in the lobby with the marble and the quiet. The revolving door is the threshold and the threshold is the oldest architectural idea in the world. The doorway between one world and another. The revolving door just made the threshold spin and the spinning never stops and the not stopping is the point. The building is always receiving. The building is always releasing. The revolving door is the breath.