Inclinometer?

I know very little if anything other than what you see.Placard says:
MANUFACTURED AND PATENTED BY
JOHNSON-FRIES MARINE CONSTRUCTIOCO.
NO. C-114 PORTLAND,OREGON
The shaft that the arm pivots on does not appear to be original in that there is a hole on both sides that a drift pin would appear to run through but the shaft has no hole.I suspect that the original connected to some portion of a control system on a ship but that is only speculation based on what I can see.