This is a rare solid brass cylinder, or machine oiler! It is marked "DETROIT LUBRICATOR CO. DETROIT U.S.A." on the largest part of the bulb shaped form of the exterior body. This oiler is 4.5" tall including the threaded ends as shown in the pictures, and is about 2.5" diameter at the widest point. The larger threads are 1/2-18 NPT threads with a place for a washer or gasket, and the top threads are 1/4-18 NPT threads. I don't think these are standard thread sizes, which in part leads me to believe this lubricator was made before pipe thread standardization, or special brass threads were used in this case. The larger thread is in very good shape, the smaller has some wear on it, but mostly intact. This is a cast brass oiler with a similar bulb shape inside to match the outside, with about 1/4" wall stock thickness. As you can see there are some dings and scratches on the outside brass, but overall a fairly nice finish. We are not sure what application this unit was made for, but it is rare. We do know that a similar bulb shape was used on the Henry Ford Quadricycle, first one built in the late 1800's, but the cylinder bulb oilers appear to have been made of glass in part. We are not sure if there was once a flip cap at the top, or if another section of oiler was once a part of this unusual casting. It is possible that this unit was made for a boiler system and other type of commercial plumbing applications, but no other information was found. Weight is about 3/4 pound. A rare oiler.