Educational toy made in plastic versions. In the mid-1950s, more explicitly engineering-themed construction toys appeared, including plastic girders, columns, and panels that could be assembled into a model curtain wall skyscraper. Later, this Girder and Panel structural system was extended to a Hydro-Dynamic setup by adding pipes, valves, tanks, nozzles, and pumps to allow construction of model plumbing, HVAC, and chemical engineering systems like a simulated distillation column. Other extensions of the system supported suburban-style housing developments (Build-A-Home), or monorail transportation systems (Skyrail). The building toy Lego was originally developed by Ole Kirk Christiansen in Billund, Denmark, in the 1930s. The name
Lego good"). This motto, which is still used today, was created by Christiansen to encourage his employees never to skimp on quality, a value he believed in strongly. By 1951 plastic toys accounted for half of the Lego company's output, even though the Danish trade magazine "Legetøjs-Tidende" ("Toy-Times"), visiting the Lego factory in Billund in the early 1950s, felt that plastic would never be able to replace traditional wooden toys. Although a common sentiment, Lego toys seem to have become a significant exception to the dislike of plastic in children's toys, due in part to the high standards set by Ole