Kai "the spy" wrote:
I don't think the Doctor actually invented the quadracycle, there. Those have been around for ages. Just not as common as the bicycle. I had thought the Doctor would know something like that.
According to Wikipedia, "The earliest recorded pedal-powered quadracycle was exhibited in 1853 at the Exhibition of the Industry of All Nations World's Fair held in New York City."
Maybe the Doctor took it for a spin? Sounds like a Doctor-y place to be.