These two blacksmiths appear in what is perhaps the most widely recognized of Muybridge's complete motion study sequences. I include it here because it is also one of the very best.
Most of Muybridge's models were University of Pennsylvania athletes, but I have to wonder how he recruited these handsome men. Did he just visit smithies around Philadelphia until he found two willing to work nude . . . and be photographed doing it? I'd love to know how that went.