While undertaking some research on the early days of Pennsylvania's East Broad Top Railroad, in the board meeting minutes I found multiple references to the Pennsylvania Railroad "broad gauge" as compared to the EBT's "narrow gauge." While I've seen present day comments about narrow gauge (2-foot), standard gauge (3-foot) and broad gauge (4'8-1/2"), they are tongue-in-cheek. This is the first authentic (1871) reference that I've come across.