“In the second place, the power of neutralizing the gravity of metals, as I have explained to you, enables us to erect works miles above the ground more easily than you do at the surface. In fact the works erect themselves and the most we do is to tether them at the proper height to keep them from going too far. When motion is required to be given them, the globes of light are sometimes attached to a car that is made to run on a single rail elliptical track, which may be suspended at any elevation and reduced to a minimum weight by proper adjustments of its gravitation, the light globe being either suspended from the car or floating above it. The elliptical orbit is inclined enough to enable gravity to propel the car. An automatic shunt turns on repulsion when the car reaches the lowest part of the orbit and it is then forwarded on the up grade portion, shunted again at the top and so on perpetually. Another machine often used is a hollow cylindrical stem suspended from the dome, having a series of wheels, concentric with the cylinder, one above another and caused to revolve horizontally at different rates, by clockwork inside the cylinder. Globes of light are suspended by long wires to these wheels, which by their revolution, at varying rates, cause the globes by centrifugal motion to describe large or small orbits as desired. All sorts of eccentric and peculiar motions are imparted to the globes by variations in the regularity of the revolutions of the wheels, the spheres falling toward the center when the motion is slow and flying outward when it is fast. The mazes of a cotillion are often imitated, and the performance is called the ‘dancing of the spheres’. This is also accompanied by music, sometimes by local bands situated on the ground playing in concert with the movement, at other times by immense instruments operated by the same machinery that drives the spheres.