My eyes are also not what the could be.

This may be part used for accurate measurement of the parallax difference on a stereoscope. You don't by chance have that as well? The 400mm seems ti be what is expected.

More modern measurements is obtained by moving the two pointers by turning a screw.

Does the relative position of the image change when turning the knob / toothed wheel?

The leather may be there for sharpening the pencil (that was before the days of ink pens) for marking the same spot on the two photos.

Thanks for your response. It looks up, not down. It's more like a surveying instrument.

The leather is a belt loop. The box was made to wear in the field, I believe, by either a wood cutter or railroad man. The instrument was held securely in place by a metal clip for travel.

I believe the instrument is a theodolite, but, I've never seen one on this type of mount.

OOPS forgot to log in

lyn

My knee jerk response was a surveyors tool yet I am confounded by the dimensional points you offered up.

Will ponder a bit more.

Photography. Surveying. Vertical.

Could possibly be an old photgrammetry instrument. That is aerial photography/ surveying.

Nice table!

Can you give us a close-up of the 'works'? Looks like there's a spirit level in there, but can't really resolve it.

Are there any manufacturer's marks? Instruments like this usually have something.

Yes, there are two levels, one circular and one linear. Between the levels in the pic is a thumb screw to adjust elevation of the eyepiece. The wheel on which the eyepiece is mounted can be ratcheted up and down. It's graduated from 16-0 by twos and from 0 to 48 beginning with 62 counting back by twos to 48. Hope that is understandable. 16-0 and 0-62, 60, 58, 56 etc.

The devise is made by Huet, Paris.

Another picture

Sounds reasonable.

A search of the 'net on Huet Paris turned up this:

Long regarded as the "Zeiss of France", Huet (pronounced "hew-AY") was the most important supplier of optical ordnance to the French during both world wars and right up through the Algerian conflicts. The quality of Huet's military binoculars is superb, and this artillery theodolite is another example of their fine workmanship. Marked with the distinctive "Huet/Paris" insignia, this unit provides azimuth and altitude .............

Huet was definitely in the business of making optics for the wars.

This could be a flat table dumpy level / theodolite.

Maybe used for surveying or pegging out a road section on a specific slope or contour.

If you look into the eye piece can you see some cross hairs? (3)

I still think areal photography formed part of it because of the 400mm interval on the scale.

Why am I not surprised that you would have the answer?

milo

I only regret that I don't have the cannon that came with the one I owned otherwise I could demonstrate the trajectory calculations this instrument was capable of (which, incidentally haven't changed to this day).

Hi Duckinthepond

"Alidade" I haven't heard the name before but you deserve a GA vote.

Regarding the 5 off topic votes - I think you did that to yourselves.

Yeah...maybe you right.......but the off tops sure can get colourful.

Imagine how boring things would get if the conversation ended at "it's an alidade"......me like this more

Here's a more modern day version of what you have...1908. Peary had a similar instrument to yours when he went to the N Pole although his consisted of having a mercury false horizon..

Hi,

This looks like a more complex instrument than mine, but functions the same, I'd think.

There are numerous scales etched into the eyepiece prisim, besides the one marked milliemes, but, my eyes aren't good enough to make them out. I'm trying to find some kid to sketch it out for me.

I do know that it was intended to be worn in the field, on the belt, so it had to be compact, and robust.

BTW, in addition to Huet, Paris the barrel is marked MOD. 780.

I've sent the pics to the WWII Museum in Washington DC to see if they have a line on it.

Cheers,

Lyn

It is possible the scales on the prism are reflected off the graduated circle and projected onto the stadia. The eyepiece might be able to focus by turning...but don't force it. It probably needs a good cleaning.

Brunton has some fixit techs capable of doing this.

This instrument was used with a chart to orient oneself to the immediate visible landscape. By using fixed points on the map one could calculate angle and distance beyond what one was able to see (that was the ordinance trajectory calculation).

It was, I believe, called the 'Jacobs' Staff' in the 1st World War.

Hello Duckinthepond:

By using fixed points on the map one could calculate angle and distance beyond what one was able to see (that was the ordinance trajectory calculation).

Look, I want to be at least fractionally correct...........So does that make it a kind of inclinometer? Or????????????

Have a great new year................

Sort of......an inclinometre measures the angle of an incline but not the distance. This instrument measured the distance (through trig functions) of specific points on a chart. It would be used in conjunction with an inclinometre that was part of the sighting and elevating mechanism on cannons and probably mortars.

This one being of French design indicates that US gunners had to learn French terminology during the 1st WW (the French and Swiss had the best optical instruments at the time).

Upon further study ...yes.......it can be used as an inclinometre!!!!

Hello Duckinthepond:

I made a similar though far less sophisticated thing to measure the satellite elevation, to set my sky TV satellite dish. Consisted of a plumb, rule, and protractor.

Have a great new year...............

That, sir, is a rudimentary precursor to the sextant originally used by Arab and Polynesian sailors to navigate by the stars.

Hi Lyn,

This might be of interest for you, there are many variations of the instrument but this one is very similar http://www.surveyhistory.org/an_alidade1.htm

The surveyhistory organisation may be interested in the information in this forum thread to add to their knowledge base.

That's it!

Thanks to all!

Great fun!!

That's it? The link says they dont know the function of all of the knobs and scales. We have more work to do Gunny.

Perhaps you are right.

Close inspection of the web photos also reveals that the boxes are different. Mine has no block with thumbscrews, nor matching holes in the opposite side. Note the picture shows the box squarely on the surface below.

My box has a leather belt loop on the back.

The instruments themselves seem to be identical in function and form, with differences attributed to different manufacturers and countries of origin. There are differences, though.

MOD in the UK is Ministry of Defence - is it the same elsewhere, or does this suggest it was supplied to the UK Govt? (open question).

Re. the instrument in question - are there any more marks (e.g. anything possibly indicating 'government property' of any state)?

The barrel is marked S.G.no 780.

Below that is Heut Paris.

There is an indecipherable stamp on the inside of the door of the box.

That's all.

Have fun, I am.

http://www.archive.org/details/americana

This is a priceless resource of US and Canadian library collections. Given time I hope it will include all the libraries of the world.

Thank you for that valuable resource. I am embarrassed to say I was unfamiliar with it. I am a collector (very novice) of books - actually more of tech manuals and general ephemera - and cherish all such resources.

For some help in pricing I have become frustratingly dependent on ABE.com

Thanks.

Hello Duckinthepond:

Very interesting article about the 700 terms used for the US Artillerymen!

GA to you sir!

Have a great new year..........

Hello Duckinthepond:

I do not know what it is but, your answer seems to be the definative one!

So is it used to line up with say the north star, that kind of thing?

Have a great new year.............

Hello Lyn,

I think it may be a theodolite or a fancy Inclinometer. Could be used in the laying of mosaic marble and stone flooring?

To all who see this I hope you had a good Xmas!

Hello lyn,

I have had my guess, but, I would love a table made from that wood!

It is gorjus!

Wow,

There's a WWII shop here in town. I'm taking the thing in to George tomorrow to see if he knows what it is.

I think Ducky has it. If I think about how the thing could be used, it makes the most sense. I'll let you all know, if he knows what it is.

BTW, the table is really the floor. My wife had it put in the whole house, mostly.

It's called Adura Luxury Plank Flooring.

Thanks for the compliment.

Agreed - the floor is spectacular.

It works really well if you have a cannon and maps that are 50,000/1. Basically, it is a trig calculator.

Hello lyn,

Be interested to see what answerd you come back with? And that is a seriously brilliant floor!

Have a great new year...............

Dunno, what it is...but I like the table top
Del