What is this?

[SonofHarold - Metal Carver]

I think this is as good a place to post this as any. It's not a machinst tool but anyway... I have had this in my tools (inhearited from a fromer father in law how passed away and was mechanical engineer) for a very long time and while I might imagine how it could be used I have no idea just what it is. There is no name or any identifying marks on it what so ever. There does not seem to be any place where it would mount or attach to something else but I think it had to go with some other equipment due to the lack of a name or trademark etc. It is obvioulsy very high precision and made very well and also has the neat little leather belt case. I think it might be used in some type of survey operation but not sure. It is about 5" long, the sq black bottom about 1/2 inch, has an eye piece that when you look through you get a split view half is through with a horiontal line and the other half is a view of the bubble level. So you could determine angles from your possition using the scale on the side which seems to graduated in degrees. What is this thing called and what is it used for in practice? Thanks in advance.

 

[benmychree]

A sighting level for grade setting.

 

[Superburban]

Look here

https://en.wikipedia.org/wiki/Topographic_Abney_level

 

[cbellanca]

It s a hand level used as a quick check for excavations and grade.

 

[SonofHarold - Metal Carver]

Great, Thanks! Pretty much used as I thought it might be.
I had tried in the past to do some searches but not knowing what the right terminology was, I never came up with anything that matched.
I used it yesterday to get a 10 degree angle set on my new grinder's tool rests. lol, a bit over kill I guess but it was what I had that would do the job.