This is a great example of a contemporary, steam-driven industrial shop. A single steam engine turns an overhead shaft, and myriad lathes, milling machines and other pieces of equipment are connected to the shaft by leather belts, on wheels of differing diameters to control the speed of the equipment. And none of these moving, spinning parts is shielded. It's an OSHA nightmare.
I once worked in a machine shop that still had the overhead shafts and belt drive mechanism still in place. It had been used in the early 20th century to as late as WW2. I am not sure if it was in place and in use before the advent of electric generator drive, though.