This oil cup was discovered in 2001 in a mass of concretion withother various tools. These tools are most likely the spilled contents of a tool box and included different sized hammer heads, a small oil can, a lead ingot, and glass from a lantern. The mass was concreted to a large copper alloy pipe.
Radiography was employed to determine the internal condition of the object and revealed the presence of a small vertical tube within the cup possibly indicating that this is a siphon oil cup. Also identifiable in the X-ray is the threading holding the cover in place along with the mounting end of the cup visible within the nut.
“From Modern American Lathe Practice” by Oscar E.Perrigo, 1907
Oil cups, such as this one, would have been mounted above rotating parts to which they lubricated. A wick was placed in the central tube and the cup was filled with oil. When the cup was full of oil, the wick prevented excess oil from pouring out and when the cup was low, the wick siphoned the remaining oil. Many cups similar to this one can be seen attached to the Monitor’s steam engine.
Upon the completion of the treatment, both the cover and nut were removed and surface detail has been revealed including machining lines.