Nintendo tumbler puzzle Nintendo tumbler puzzle The Nintendo tumbler puzzle, also known as the "Ten Billion Barrel" in English and originally in Japanese, is a mathematical puzzle in the style of Rubik's Cube. It was invented by Gunpei Yokoi of Nintendo in 1980 and was covered by (until the patent expired in March 1995 due to non-payment of a maintenance fee). It consists of a "cylinder" of transparent plastic divided into six levels, together with a black plastic "frame". The frame consists of upper and lower discs that are joined together through the middle of the cylinder. The top and bottom levels of
Howard Davis (professor of architecture) Howard Davis (professor of architecture) Howard Davis is an American writer and professor of architecture at the University of Oregon in Eugene. A native of New York City, he studied physics at Cooper Union and at Northwestern University and received a master's degree in architecture from the University of California, Berkeley, where he worked with Christopher Alexander. He has worked on projects in the Pacific Northwest, India, England, Mexico and Israel. He is known for his research into vernacular architecture and building history, published in the book "The Culture of Building" (1999, reprinted in paperback 2006). He also collaborated with