Armillary spheres are the last things one might expect to see amid the warren of streets in the financial district of Lower Manhattan. But here they are, four of them, dangling like ornaments from the arched ceiling of Federal Reserve Plaza, just three blocks from Wall Street and the New York Stock Exchange. These intersecting hoops of antiquity (their name comes from the Latin armilla, “bracelet” or “iron ring”) were teaching tools the illustrated the geocentric universe. With a model of Earth at their center, the various angled rings represented important cosmic coordinates where one might track the movements of the Sun, Moon and planets on the sky. These armillaries are also tipped away from vertical to represent the actual angle of Earth’s axis compared with the plane of our orbit around the Sun. The Federal Reserve Building, its massive stones plainly visible through the last arch in the rear, is said to contain more gold than is stored in Fort Knox, Kentucky.