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Antiques! => Antique Questions Forum => Topic started by: ppgs on June 04, 2010, 08:17:38 am
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This is some type of navigation or drawing tool passed down in my family from my grandfather. It seems to be made of bone (or ivory) with a carved wooden inlay. The bone is carved and the straight measurements are marked at 1 inch intervals (divided into 10 spaces). The measurements on the curved section is marked in 11 segments, each divided by 4. The piece pivots and the curved part slides nicely through a space in the straight edge. The pivot pin seems to be made out of metal but is is very small. One of the straight sides has a small hole is the very bottom where is looks like something could be inserted.
Does anyone have any idea what this might be? Does it look like it would be really old? My grandfather and mother have both passed away and I am not sure who else to ask. Thank you so much for any help you can provide.
Thanks again,
Sean
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Oh Good Lord that is lovely!
I think (emphasis on think) what you have there is a protractor, used in drafting or cartography, rather than a sextant, or an octant, used in navigation or surveying. But I could be wrong on that, especially since I'm not locating one quite like yours. I'm still looking and will keep at it.
The folks here at the Compass Museum could probably help you identify what industry it was used in:
http://www.compassmuseum.com/ (http://www.compassmuseum.com/)
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If I am correct that this is an antique protractor, you would use it like this:
Lay it flat on a piece of paper, with one of the straight edges aligned straight, at 90 degrees to the edge of the paper. Move the other straight piece along the curve, setting it to 45 degrees or whatever angle you need. Then you take your drafting pencil and draw along the angle.
I'm pretty sure this is how it was used, but I'd like to find a similar example before saying that for sure. Still looking as I wipe the drool off my keyboard. LOVE IT!!
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This one is a little different, but the principle is the same:
(http://www.micromark.com/RS/SR/Product/60299_R.jpg)
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OH my, while I was typing 3 new replies came in, but will post anyway.
That could very well be a nautical "dividing protractor/compass"
Ten (10) grids per inch is quite common on drawing/drafting rulers. (especially if they are metric ;D)
Is the curved section not actually 12 large segments of 4 small segments each?
And after studying it for almost an hour I am going to make some wild guesses, to wit: ;D ;D
With 12 large segments it could mean that each of the 12 segment = 7.5 degrees of the 90 degree maxmium arc. (12 x 7.5 = 90)
And the 3 grid marks (separating each of the 4 small segments) would then equal 2.5 degrees of arc.
So, the 1st Grid mark past the 2nd Large segment mark would be equal to 17.5 degrees of arc. (2Lsm x 7.5) + (1Gm x 2.5) = (15) + (2.5) = 17.5 degrees
The hole at the end of the straight edge could/would be used for inserting a pencil lead to draw an arc.
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Yes Cogar! It is 12 segments, exactly - each divided by 4. That information is so helpful. I will also try to contact the compassmuseum as talesofthesevenseas suggested. Thank you so much for spending time to look at it. If there is interest from anyone else on the board I can take some macro shots and post it. Any other thoughts would be very helpful. Thanks.
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Good Golly Miss Molly! That is a tool collector's dream item! I am almost certain it is ivory. The small hole you referred to is probably for an alignment pin so when it is closed the two arms are held straight and not warp. Just guessing as all old rules had alignment pins to keep them straight when closed. I am guessing this is an angle finder such as what a protractor is used for as tales mentioned. Where was your grandfather's family from? This may be European. I have a number of tool books and will browse them later.
That is one beautiful heirloom! Treasure it!
Are the measurements on the straight edges in cm/mm? Can you post some closeups? Where is the hole you are talking about? I do not find anything exactly like this in any of my books yet. I am still thinking this is of European origin.
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Wayward and everyone else. Than you so much for your interest. I have already learned a lot about this family heirloom which is mysterious to me. Here are some additional photos with details and a ruler for scale. The major marks are not inches, they are smaller. The minor curved marks are smaller than centimeters. I hope these additional photos are interesting to you.
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Continued...
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Continued...
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Was anyone in your family in the hat business many years ago? The inside scale on the curved piece seems to correspond to a scale used to measure hat size. I am wondering if there are holes in the ends of the straight rules where a circular band may have been fastened at one time. See photo...
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Please, please, never sell this little gem!!!!
You are so lucky to have this as a part of your family history.
I'm with Tales, and wiping the drool off my keyboard.
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Looking at the 1st photo with the ruler on it:
a scale on your rule of 42 is equal to: -3 ½ inches or 8.8 centimeters, or,
36 = 7.6 cm ….. 33 = 7 cm …. 24 = 5 cm …. 15 = 3 cm
Which don’t make sense to me therefore I will assume you have a “Barnstick” type instrument that could be old as dirt. ;D ;D
Now for those who don’t know what a “Barnstick” is, ….. it is a fairly precise instrument made by farmers of old when they needed to build themselves a barn. Since they didn’t have a tape measure or a rule they would whittle themselves out a pretty new “stick” of wood about ¾ to an inch square and yea long (between 3ft & 6ft, I guess, it didn’t matter). And they would use that Barnstick to measure all the dimensions of their new barn. Like 20 “sticks” long, 10 “sticks” wide and 12 ½ “sticks” high. And they would cut little “notches” all over that “stick” for other dimensions, and thus they could measure how wide or long the boards n’ beams n’ rafters, etc., needed to be cut for building their barn.
Your instrument could be so old that whoever made it chose the “measurement scale” to fit the size of the physical instrument, …… aka: the Barnstick.
Whatta I know, ….. it makes for a cute story. Cheers
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My guess is it's some sort of carpentry tool. The modern equivalent would be called a bevel square. You set it to the angle of one piece of wood and then transfer and scribe that angle to another piece so you can duplicate it. And since it looks like scrimshaw I'm guessing it was used in boat building.
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That sounds like a good guess, actually. I live near the Peabody Essex museum in Salem, MA and I think maybe they might be able to ell me more about it. Everyone here has been so helpful. I love all of the ideas. Any other insights would be very welcome!
-Sean
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Here's my two cents. This thing looks a little small to me to be a carpentry tool used in building ships. Those beams and planks were huge. It also strikes me as a little too fancy, and not beat up enough to have been really used for any kind of rough carpentry work. I could be wrong. Does an architect use anything like this?
If I had to guess a time period for this, I would have to go OLD. Early sixteenth century? I base this guess on the fact that the measurments are obveously not close to standard (as I would expect from something later) and on the style of the carvings. Those numerals look consistant with how people at that time wrote their numbers. The five is a dead ringer.
I would expect more patina on the wood, but i'm sure its an exotic wood, and i'm no expert on how those woods age. Whoever used this was no pauper. This is a finely crafted piece made of rare materials. I would love to know where this came from and what it was for!
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I think it's actually a scaling protractor used by wood carvers (cabinet-makers) , used in conjuntion with (metal or metal-pointed) dividers .
Please correct me if I'm wrong !
Very nice little tool , ppgs .
It's a keeper !
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This beautiful tool is just amazing, you have an amazing piece of history. Reminds me of the sundial that was on Pawn Stars. Same style, material and age. Did anyone else see that episode? I can try to find the link for those who haven't. Here's the dial, gotta find the video.
http://www.thepawnshow.com/?s=sundial
Found it, here's the videos.
http://www.youtube.com/watch?v=pIC4BZZZ0DE <---intro
http://www.youtube.com/watch?v=6ID50WbWK8M <---conclusion.
Just to show the style of that age. -> http://cgi.ebay.com/SILVER-GILT-AUGSBURG-COMPASS-SUNDIAL-17TH-18TH-CENTURY-/140362649864?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item20ae441108
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How about it being an octant or quadrant
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The measurements on the inside arc piece are divided by blocks into fourths and further divided by dots into eigths. The scale goes from 0 to 12. The 'rule' does not open fully to make a 90 degree measurement so this being an angle finder can be ruled out IMO. The measurements on the outside rules appear to be 2cm = 10 with graduations of tenths which makes zero sense. The measurements do not equal inches going by the tape laid next to the markings. I have looked through all my books and the web and not much comes close to what this was used for. I do not think it is a scribe missing its' points as there is nothing to lock the center arc to keep it from opening/closing when in use. I have looked at octant, quadrant, sector, bevel finder, protractor, etc. This must have been a specialized tool for some trade and it would be very helpful if we knew what ppgs' grandfather did or his grandfather's grandfather did etc. Judging by the decoration and carving and from what I have gleaned, I think it is 18th century or even older as Skinny mentioned and also European but not British. The hat measuring device (French) comes close as the graduations on the arc are 1-7 but the band is missing. It is one beautiful tool and another conundrum to be solved.
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Are we sure it doesn't (or didn't) open up to a ninety degree angle?
I haven't seen a pic of it fully open. When it's closed, it looks like (at the top) two forty fives, which should allow for a ninety when fully open. Of course, I wouldn't be at all suprised if the curved rule is bowed from age that it would hang up near the end and not allow for the piece to open all the way.
When this was used, it should have been able to open far enough for all of the measurment lines on the curved ruler to be on the inside of the angle, and for the hinge to be fully closed.
ppgs, will this thing still open all the way, or is it open as far as it will go in the pics?
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This is the best rendering of what it would look like opened up. The markings on the arc would be short and the arc would also be short. The arc should extend past the left arm or there would be problems in use. The arc end is ragged so it may have been broken but the markings also stop so it appears it was made that way.
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This is the best rendering of what it would look like opened up. The markings on the arc would be short and the arc would also be short. The arc should extend past the left arm or there would be problems in use. The arc end is ragged so it may have been broken but the markings also stop so it appears it was made that way.
Not to be a pain in the butt, but I don't really understand what your saying. The representation you just showed depicts an angle that's MORE than ninety. To get a to ninety, just draw your line from the pin (in the hinge) to the very last mark on the curved rule. You may be right that it would then go on to open even further, but I think myself that it would have stoped around the ninety degree mark. I would say that opening up to a full square leaves this piece in the running as an angle finder.
I wouldn't say the arc would have to extend past the left arm, as long as it doesn't come completely out of it when its open. It doesn't look like it would come out to me, but without being able to open it all the way, its tough to say.
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Skinny, my reply was lost (said I double posted but it is not here) so I see what you are saying. My original crude lines are past 90. I have monkeyed with the image so the vertical goes straight up from the first vertical line on the bottom rule arm. It cuts the arc at about the last line which would be 12. If this were an angle finder I would expect this number to be 9. I may be missing something. The key to this is what do the measurements on the arc measure? The arc arm stays in the vertical so that is good.
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It's definitly an angle finder. I've attached a picture of a modern device that would acomplish the same task, although it's design is different. The mathematics are a complete mystery. A full circle would be called 480 degrees according to this device. They're using no forms of measurment that i've ever seen. This is one of the reasons that I put an age estimate of early 1500's on this thing. Some sort of local measuring system. European for sure. This is a unique treasure if you ask me. Probably on of a kind.
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All the measurements on this are baffling. Skinny, are you familiar with cartography (I am not)? I am wondering what ancient map maker's used. Would these numbers mean anything with longitude or latitude or degrees or ? I am familiar with the angle finder you posted but these markings on this piece are a wonderment.
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All of the old maps i've seen (with longitude and latitued marked on them) used the same standard system. The poles were ninety degrees and everything went from there. I couldn't say this device wasn't used in making or interpreting maps, but I can't understand how it could have been used in that purpose.
I would just have to conclude that this thing is marked with some private, or local, or even regonal form of measurement that has long ago ceased to be used. There's no telling how old this thing is. I would just have to advise ppgs to try to consult some real experts, and if you do find anything out, let us know!
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I think contacting that compass museum would be a good way to determine it's specific use and age. We've got the general idea, but the specific industry is still a mystery and I think it is going to need a specialist in that field to say exactly how it was used. (My two dubloons worth there!)
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I think I know what this is. It's a carpenters tool used in framing wood roofs. The reason the numbers on the curved part don't make sense is they aren't degrees. The are numbers used to mark or measure roof pitch. Pitch is measured in inches of rise in 12 inches of horizontal run. If you place the lower arm along the bottom edge of a board and then set the swing arm at 6 and then draw a line along that arm you would have a 6 and 12 pitch. Once that line is established you can then draw your top cut and bottom cut on your rafters. The same system is still used today although there are better tools, like framing squares, speed squares and so on. This piece looks European in origin.
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You might just be right on that Syl! Good call! All the way straight up comes out at 12/12!
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I can't find one exactly like this device, but this is the general idea, to help with the visual on roof pitch:
(http://promotional-products.org/components/com_virtuemart/shop_image/product/305089_300.jpg)
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Don't think it's for roof .
Hey ... howsa bout a gunners quadrant ?
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While this whole object's use is a mystery, doesn't it look like there are some intials incorporated in the engraving? There is a tulip, a flower, and what looks like 2 letters. Possibly a T or P and an S?
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While this whole object's use is a mystery, doesn't it look like there are some intials incorporated in the engraving? There is a tulip, a flower, and what looks like 2 letters. Possibly a T or P and an S?
I noticed that also. Looks like a T and an S.
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I think I know what this is. It's a carpenters tool used in framing wood roofs. The reason the numbers on the curved part don't make sense is they aren't degrees. The are numbers used to mark or measure roof pitch. Pitch is measured in inches of rise in 12 inches of horizontal run.
Syl, only if cutting roof rafters for doll houses, ;D it is only 3 1/2" on each side arm.
I think the "dots" in the squares of the arc are just decorations.
And I agree with Skinny, it does open to 90 degrees, see pic pelow.
One has to be careful looking at the picures, especially the ones with the tape measure because of the angle to vertical the pictures were taken and/or the per say parallax.
I think I got it, I think I got it. …… It’s 16th Century French. See below and the pic w/ruler.
The map scale that was used for these maps then was in the old units of measurement:
1 ligne=100 toise.
One toise (English fathom) was equal to 6 pieds (English feet), one pied (English foot) was equal to 12 pouces (English inches), and one pouce was equal to 12 lignes (English lines). So one ligne (1/12 of an inch) on the map was equal to 100 fathoms (600 feet) on the ground...thus a modern scale, or more properly, the repesentative fraction, of these maps is 1:86,400 (or 1 : 6x12x12x100). http://www.informatics.org/france/maps.html (http://www.informatics.org/france/maps.html)
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Hold on a sec gang, remember that architectural DRAFTSMEN have to draw out the roof pitch, and also remember that it is not at all necessary for a pitch guage to be large, just because the roof is. The proportions have nothing to do with it, it is all about determining the angle. Typically a drafter draws a horizontal line (the run) with 12 units of measure and a varying vertical measure (the rise) and then you draw a line from the end of one to the end of the other, and that's your angle. But this little gadget would make it SO easy! It makes perfect sense and if you were a carpenter you could carry this with you and check the angle as you were building. I think Syl's got the right idea. I really hope that this one goes to a museum or other authority to get checked out so that we can learn what it's true use was! :) VERY interesting topic this has been!
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You have a truly wonderful piece of history there!
I would bet that 1) You had a drafting/surveying engineer/designer in the family (I don't think this fine piece would have been used by an everyday craftsman no matter the era) 2) it is worth $$$$$$$$$$
AND IT LOOKS FRENCH!!!!!!!!!!!!!!!!!!!!!!!
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I believe the dots in the arc are eigth divisions, the squares or small boxes are fourth divisions and the longer line in the center is a half. What it measures is the BIG question. I can't fathom what cogar is talking about because after looking at all this my eyes are pied, and my feet are asleep. I have to go lay on the ground and stretch my inches out fully to scale.
I hope ppgs takes this someplace informative (like a museum) and someone can tell us what it is and what it really does.
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waywardangler...LOL OLOL!
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Tales, ....... Syl stated and I agree that "Pitch is measured in inches of rise in 12 inches of horizontal run", ....... but the horizontal "scale" on that "thingy" is not in inches.
The circular “scale” consists of 12 large segments per 90 degrees of arc, …. with one (1) ½ segment mark and three (3) ¼ segment marks, …. (and if Wayward is right about the "dots" in the squares, …. seven (7) 1/8 segment marks) …. per each one of the 12 segments or per ¼ of a circle. That means a full circle would equal either 192 or (including the dots) 384 increments.
Which doesn’t make a lot of sense for a 360 degree circle.
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My first instinct was "architect". An affluent professional could afford a fancy tool like this. Cougar, I'm glad you agree that it's sixteenth century. I felt like I was kind of going out on a limb with that one.
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Pitch can be calculated in any unit of measure. You can have 12 lengths of your nose horizontally, and 6 lengths of your nose vertically, and the angle will be the same as if you drew it in inches. Architectural drawings are scale drawings and what scale they are drawn in differs from drawing to drawing. Usually the roof pitch appears as a simple triangular diagram off to the side of the drawing like this:
(http://www.loghomedesign.ca/images/newsletter/roofpitch.jpg)
On the curved part of the tool, you are not PRODUCING the angle, but you are READING it, just like you would read it off a screen, just like you would if it was a digital read out. It's quite an ingenious and deceptively simple little device.
I was a drafter for 18 years and taught vocational drafting school for 9 of them. I think Syl got it right. The way to find out for sure would be to draw out roof pitch triangles to scale at 1/12, 2/12, 3/12 etc. roof pitch, and see if when you set the device to READ OUT 1, 2, 3 along the curve, if the straight edges match the roof pitch diagrams. If they do, that's got to be it. I'm putting my money on Syl this time.
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When I get home tonight, I'm going to draw out a scale drawing like this device to show what I mean in the above post. I think that will make it a little clearer.
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I did a sketch to show you what I mean. I really think Syl is right, that this is roof pitch. You would use the device like this:
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Zoom up on the photo I posted above so that you can see the numbers on the curve. Read the number on the curve at the point where the angle that changes crosses the curve. Look at the houses below each setting to see how the angle on the device, transfers to an actual roof. See what I mean?
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That sounds good to me Tales. I am disagreeing with Skinny and cogar by 100 years and going with 17th century and only because tulips were a hot engraving item during that time frame (I Googled it). But and this is a big but, I don't know anything else about the 16th or 17th century. I do not remember who said what about that number 2 that looks like a Z but that might be the 16th century way to write a 2? I agree this was a tool of someone affluent just by the exquisite carving and detail. I do not think a common tradesman could not afford such a decorated item.
I hope we have closure to this sometime.
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I agree. I think this Syl nailed it, (pardon the architectural pun!) but it would really be great if this could be confirmed by an authority.
PPGS, would you consider emailing some photos to that compass museum posted earlier, or perhaps the MIT Museum of Engineering or some other technical museum? I think with such a rare and unique instrument, I think you will have no problem getting them to take a look at your photos. A museum specializing in architecture might also be a good option. *gives PPGS arm a twist*
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Yes Please take it to a have it really studied ;D, This thread is really making my head Spin :o I did very bad in math and also flunked my drafting class. Actually I have really enjoyed this thread. I thought I would throw my 2 cents in here, MMmmmm, let me think. Let see, I know, I Know ..... It's a Tool ::)
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Ironlord, you rock for simplifying this stupefying thread. My head spun out awhile ago and I am in the ditch trying to get back on the track. ;D
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I am a total math-phobic, but I love to draw so that is how I ended up a drafter and it eventually led to technical writing, which is what I do now. I'm glad I'm not the only one who hates math with a passion!
I agree this has been a REALLY interesting topic and I've really enjoyed following this one!
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I like to add & subtract ..... divide & conquer isn't my cup of tea either .
Thing that's bugging me the most about this interesting item is that appears as if it's been broken , and possibly missing the key part(s?) to render out all of our mis-identifications , dang it !
I'd be emailing national tool/science museums , if it were mine .
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Okay....did we ever establish the material it is made from?
It could also be celluloid!!!!!!!!! (Like dominoes were made from) These did make these out of celluloid in the 19th C.
If I knew of a site to send it to...I would with the pic that is already posted!
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KC, I do not believe we ever determined what it is made of. I think it is ivory but it may be bone. None of the closeups are real sharp and the material exhibits qualities of both. I do not see the cross hatching grain of ivory and I do not see the dark flecks in bone. I also do not see the parallel lines in celluloid. We are hoping ppgs would take this item to an expert to have it looked at in person to determine what it actually measures or was used for. Tales twisted ppgs arm but have not heard if that worked...yet.
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Just for grins...like this site for reference....ivory measuring devices
http://www.gilai.com/cat_41/Length-Measuring/1 (http://www.gilai.com/cat_41/Length-Measuring/1)