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 minifigure In 2010 more than 300 new minifigures were introduced. Minifigures generally feature six parts (widely referred to as "tools" in the toy industry): head, torso, hips, arms, hands, and legs; these six parts allow seven points of articulation: swivel head, swivel arms, swivel wrists, and swivel legs. Minifigures are usually packaged as three separate parts in Lego sets: head, torso and legs. The plastic is acrylonitrile butadiene styrene (ABS), a tough material that makes LEGO figures durable. The plastic is melted into specially designed molds that produce the different parts of the minifigure. Some of the molds are also accessories