Good Eye: From beer suds to soap suds, this modernist factory building stays busy

We keep hearing about how America doesn't make anything anymore, yet a low-slung modernist factory has been chugging along a mere two blocks north of Philadelphia's downtown for more than 70 years. Today, its assembly lines turn out a variety of industrial cleaners for National Chemical Laboratories. But when the plant at 10th and Callowhill opened in 1935, the liquid that coursed through its network of pipes was beer.