What Is It?

I've had this thing for 30 years. It came out of a military depot. I'm sure it is US military, and it probably is part of some kind of gunner's quadrant, but I'm just curious if anyone has a more specific idea. The base is 7" long and it's 3" high. All steel with early tint olive drab paint. The machined bottom obviously is to be mounted on another piece of machinery. The slot in the device would fit over a vertical rib of about 2mm thickness and about 1" in height, max., and it probably is made to slide for adjustment. One end of the slot in the base is open. Strangely, it also has an index mark at the bottom which becomes visible when the degree wheel is rotated 180 degrees. The degree markings go to 90 degrees in each direction. I have not been able to find any other marking on it of any kind. The spirit level is adjustable and in perfect shape. The basic structure is four parts; two frame halves, the armature and spirit level. It is put together with locating pins and screws.

https://www.milsurps.com/images/impo...DSC00783-1.jpg
https://www.milsurps.com/images/impo...DSC00784-1.jpg
https://www.milsurps.com/images/impo...DSC00785-1.jpg
https://www.milsurps.com/images/impo...DSC00786-1.jpg

Sorry, I posted this in the wrong place - by a mile! I meant to post it on the militaria collectors forum and got distracted. That's a great forum for equipment, uniforms, etc.

Machinist combination square. At least this is part of it. You seem to be missing the greatest part...

Thanks, BAR, that's it. I guess the only thing interesting about it is the militray connection.

I guess it would be on issue to the military engineers, the ones that actually build things. You can see how the square was pilfered along the way.