Adjusting the bottom tension is generally set at the factory and shouldn't need adjustment. The tension on the bobbin case is controlled by a small screw and a curved metal band. Turn the screw that is located next to the thread opening. Remember: Righty, tighty; lefty, loosey!
Catenary Veil by Paredes+Alemán arquitectos - Bead-chain curves of different length, all taking their shape through gravity. It is located in front of a set of escalators, so that viewers moving up or down can see the slow overlapping of the curves forming a series of meshes of different densities.