First it was waterpower, then it was coal fired steam power.  3000 horse power boilers feeding line shafting through out a huge multi storied brick New England Mill.   Machines like these - drill presses, planers, lathes, - all turning, mechanically powered through line shafts and leather belting.   

Amazing.    

There is something magical, mesmerizing, about rotation - about circles spinning round and round.  

Probably why we can't resist buying cars.  Mesmerizing.

Perpetual motion. (we all think about it as round and round - but it might be linear!)

Factories full of us - a century ago.