Roundabout constructed in 1972 in Swindon, Wiltshire, United Kingdom, designed by Frank Blackmore, inventor of the mini-roundabout. The roundabout joins five roads and consists of a two-way road around the central island, with five mini-roundabouts meeting the incoming roads. The name derives from the popular children's television series, "The Magic Roundabout", and is considered "magic" because traffic flows in both clockwise and anticlockwise directions. This is achieved by surrounding the main island with one smaller roundabout per entry/exit street. This pattern directs traffic in the usual clockwise (in LHT installations) or counter-clockwise (in RHD installations) manner around each mini-roundabout. Exiting the
Magic circle (mathematics) Magic circle (mathematics) Magic circles were invented by the Song dynasty (960–1279) Chinese mathematician Yang Hui (c. 1238–1298). It is the arrangement of natural numbers on circles where the sum of the numbers on each circle and the sum of numbers on diameter are identical. One of his magic circles was constructed from 33 natural numbers from 1 to 33 arranged on four concentric circles, with 9 at the center. Yang Hui's magic circle series was published in his "Xugu Zhaiqi Suanfa"《續古摘奇算法》 (Sequel to Excerpts of Mathematical Wonders) of 1275. His magic circle series includes: magic 5 circles in square,