About 5" long when all screwed together.......all comes apart. Some kind of vent? All brass construction. Was in a box of 20's-30's auto parts/tools. I cleaned it up to try to find a name or a number on it............NOTHING> My FIL thinks a part for a lamp?
Looking at the internal parts and design it looks to me like a steam whistle. Like I posted earlier it is missing the valve part on the bottom. Here is a design see the internals and how they are close.