The transom was the window above the door. A rectangle of glass in a wooden frame that opened on a hinge and let the air pass through the apartment when every window was closed. The transom was the ventilation system of the tenement. The transom was the lung of the hallway.

You opened the transom in summer and the air from the hall mixed with the air in the apartment and the hall air was cooler because the hall had no sun. The building shared its breath. Your neighbor's cooking came through the transom and your radio went out through the transom and the hallway was the commons. The transom made the building one organism. Every apartment was a cell and the transom was the membrane.

My grandmother on Delancey Street kept her transom open year round. She said a closed transom means you do not trust your neighbors. She said the transom is how you know who is home and who is not. She could tell you who was cooking what on every floor just from the air that came through her transom. The transom was the newspaper of the hallway.

The transom let in light. The hallways in the old tenements had no windows. The transom above each door let a slice of apartment light into the hall. You walked down a dark hallway and you could see which apartments were awake by the glow above the door. The transom was the nightlight of the building.

They sealed the transoms. Fire code. The transom was a draft path and the draft fed the fire and the fire moved through the transoms from apartment to apartment. So they sealed them. Painted shut or replaced with drywall. The building stopped breathing. The hallway went dark. The apartments became boxes and the boxes did not share air and the air conditioning replaced the transom the way the elevator replaced the stairs. It works. But the building is no longer one thing.

See also: Fire Escape, Clothesline