Old Brass Inkwell?

[Glenn C]

I found this at a site that dates between 1700 to mid 1800s. It is solid brass and has the bottom ground slightly maybe to remove a makers mark, looks like a u in the photo ..U.S?..Also a hole in the bottom. There was shipping in the area. Could this hole be there to fixate it to a table for rough waters..just a guess im putting out there. Thanks in advance!

 

[GB1]

looks like it

 

[Tony in SC]

Why would an inkwell have a hole in the bottom? Maybe it had a pedastal that has been cut off?