Read this and answer the question. If the question is unanswerable, say "unanswerable".

The first elevator shaft preceded the first elevator by four years. Construction for Peter Cooper's Cooper Union Foundation building in New York began in 1853. An elevator shaft was included in the design, because Cooper was confident that a safe passenger elevator would soon be invented. The shaft was cylindrical because Cooper thought it was the most efficient design. Later, Otis designed a special elevator for the building. Today the Otis Elevator Company, now a subsidiary of United Technologies Corporation, is the world's largest manufacturer of vertical transport systems.

Which was built first, the first elevator shaft or the first elevator?
first elevator shaft