Water wheel a chain basket (German: Kettenkorb) on the axle of the wheel. It is essential that the wheel have braking equipment to be able to stop the wheel (known as a braking wheel). The oldest known drawing of a reversible water wheel was by Georgius Agricola and dates to 1556. Two early improvements were suspension wheels and rim gearing. Suspension wheels are constructed in the same manner as a bicycle wheel, the rim being supported under tension from the hub- this led to larger lighter wheels than the former design where the heavy spokes were under compression. Rim-gearing entailed adding a
Are Years What? (for Marianne Moore) mobile with wire, shaped like a "V". "Are Years What? (for Marianne Moore)" is signature of di Suvero's monumental early 1960s "open-work constructions." These works utilize cast-off construction materials like chains, metal bars, and ladders. This sculpture is the first that di Suvero built, from beginning to end, with I-beams and using a crane, solely by himself. "Are Years What?" was originally in the collection of the artist, then the collection of Enrico Martignoni of Winnemucca, Nevada. Hirshhorn director James Demetrion first saw the sculpture when it was on display in Brooklyn's Prospect Park. The sculpture was acquired by the