When the SS Republic was built in 1853, brass and bronze porthole fittings with heavy glass had been in use for a number of years and yet were still a novelty on many ships. No doubt the Republic’s portholes were an advantage to the passengers aboard ship.
Their function when open permitted light and fresh air to enter the dark and damp below-deck quarters of the vessel. It also afforded below-deck occupants a limited, but often much needed view to the outside world. When closed, the portholes were intended to provide a strong water-tight and weather-tight barrier.
Seventeen portholes were recovered from the wreck site in various shapes and sizes. All of the examples were discovered with their thick glass still intact. Much of the porthole's weight in fact comes from its glass, which on ships can be as much as two inches thick. Bronze and brass in particular, was a favored metal component due to their resistance to saltwater corrosion. Further, the design of the porthole was intended to achieve its humble purposes without sacrificing the integrity of the ship's hull. The porthole's thick glass and rugged construction, tightly spaced fasteners, and even its round shape, all contributed to maintaining hull strength.