Mounted atop a sturdy wooden base and paired uprights is a large blown-glass sphere or globe, with a small, turned wooden wheel attached to it. The sphere rests on a small, leather-covered pad. A slender iron rod passes through the wooden wheel and the sphere, holding them in place between the two wooden uprights of the frame, and permitting them to revolve freely between them. Below the spinning globe, the wooden frame supports a large, vertically mounted wooden wheel with a heavy, turned rim. The wheel is fixed in position by a rod running through its hub, and terminating in a handle by which the wheel can be turned. A long, leather cord or strap runs around the rim of the large wheel and connects it to the small wheel and globe mounted above it. Turning the larger wheel transfers the motion to the smaller wheel, causing the sphere to spin in position. The friction created between the spinning globe and the leather pad creates a static electrical charge in the globe. A metal point, or set of points, touched to the glass will draw off the charge. Copying machines and computer printers employ the same principle.