I did not know this. Exactly 100 years ago this week the first Ferris Wheel went into operation at the Chicago World's fair. Built by the Pittsburgh firm of one George Ferris. Who knew? Why was Ferris here in Pittsburgh? He was not from Pittsburgh, but was a young entrepreneurial engineer specialized in steel construction, so this was the place to be. Just think it took most of a century for folks to start talking about industrial clusters and even longer before anyone mentions talent migration.
Related (circularly?) is this little snippet of what physicists must doodle about (h/t ): Could a high-speed train run through a vertical loop, like a rollercoaster, with the passengers staying comfortable?
Of course many knew all that, and I would have known all that Pittsburgh history if I watched more Rick Sebak.