Help Identifying what may be a Nautical Instrument by WALKER

[in2harmony]

Hi - I'm wondering if anyone can positively identify this brass instrument. It's marked WALKERS PATENT and as far as I can ascertain this relates to a Birmingham manufacturer Thomas Walker who made Ship's Logs (a means of measuring speed and distance travelled). This item looks like it might attach to something else but is in its own metal box - the tube appears to be a sight although has no optics in it. It also has a scale that probably shows angles, so I'm guessing it's either something similar to a sextant or possibly to do with obtaining an inclination for a gun??

I've spent ages on Google but just can't find anything quite like it, so would really like to know something about it but even some suggested avenues to explore would be great.

Thanks in advance.

[mart]

Possibly an inclinometer??  To measure list to port or starboard side ??

[cogar]

I think Mart is correct

And it appears to me to function via the same principle as a plumb-bob .. only it has a built-in scale for determining the “angle of tilt” … or “angle to vertical”.

My guess is, it functions as follows:

It is hung on a nail to freely “swing”, …. the thumb-screw is loosened so that the “sight tube” can be slid left or right …… to align it with a reference “point” on a far wall.

Sliding the “sight tube” in the two ferrules will cause a change in the “center-of-gravity” …. and that change can then be read in “degrees” via the scale. 

[in2harmony]

Thank you MART & COGAR - your suggestion of how to use it seems logical and I'll have to give it a go. I've just Googled again with this in mind and still haven't found another example, so if anyone else can add anything, I'd still be interested.

[mart]

Try what I did,, look for a similar shape,, triangular !!  That's how I found a similar one but a bit older !!