Danvers, Mass.-based OSRAM SYLVANIA recently celebrated its centennial at its St. Mary’s, Penn., plant. The light bulb manufacturing plant, which now produces two million light bulbs a day, opened as the Novelty Incandescent Lamp Company in 1906.

Currently, 400 people work three shifts a day, seven days a week, and manufacture more than 600 million light bulbs annually at the St. Mary’s location.