The water tank sat on the roof like a wooden barrel from another century. Every building had one because the city could only push water up six floors and after that you were on your own. The water tank was the reason you had water pressure on the tenth floor. Gravity did the work. The pump filled the tank and the tank fed the building and the building did not know or care how the water got there.

The water tank was made of cedar because cedar does not rot in water. The cooper built it on the roof by hand. He bent the staves and fitted the hoops and sealed the joints and the tank held ten thousand gallons and it held them for fifty years. The cooper was the last craftsman on the skyline. Everybody else up there was welding steel. The cooper was bending wood.

Three families have built the water tanks in New York for over a hundred years. Rosenwach and Isseks Brothers and the third one nobody remembers. They built them the same way they built them in 1890. No change. No upgrade. No innovation. Because the design worked. The water tank is the most conservative piece of technology in a city that tears down everything that works.

I looked at the water tanks from the roof on East Seventh Street and they looked like a herd of wooden animals standing on top of the buildings. Every tank was a slightly different shade because the cedar aged differently in different light. The water tank was the only thing on the skyline that looked alive. The steel was dead. The glass was dead. The wood was breathing.

They want to replace the water tanks with fiberglass. Fiberglass is lighter and cheaper and it does not need a cooper. But fiberglass does not age. It does not darken in the rain. It does not look like it belongs. The wooden water tank earned its place on the roof by lasting. The fiberglass tank is placed there by a crane and it looks like a mistake. The skyline is losing its oldest signature one roof at a time.

See also: Roof Garden, Tar Beach