At the turn of the 19th century, steam-powered transport on both land and sea began to make its appearance becoming ever more dominant as the century progressed. Steam engines were the moving force behind the Industrial Revolution and saw widespread commercial use driving machinery in factories and mills, powering pumping stations and transportation including railway locomotives and passenger and cargo ships such as the SS Republic.
The Republic housed a vertical walking beam steam engine with twin return-flue boilers and other related machinery built by Charles Reeder and Sons of Baltimore. Reeder was a pioneering firm in steam engine development and had prior to the Republic, built several famous railroad locomotive and steamship engines.
The excavation of the wreck site produced one boiler sight glass, also known as a water gauge, a transparent tube through which the operator of the ship's boiler could readily observe the level of liquid contained within. This seemingly simple glass tube, amazingly intact after nearly 140 years on the seabed, was connected to the bottom of the boiler tank at one end, and the top of the tank at the other. Ideally, the level of liquid in the sight glass was supposed to be the same as the level of liquid in the tank.
One of the few ship parts recovered from the SS Republic, this rare artifact had been located inside the engine room on the boiler. Excavating the piece entailed carefully maneuvering the Remotely Operated Vehicle (ROV) around the walking beam engine and other large structures located in the room.