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Very Rare 1816 Vernier Caliper is now in my collection!

rivett608

Diamond
Joined
Oct 25, 2002
Location
Kansas City, Mo.
Sometimes you just get lucky. About a month ago I went to a very high quality antique shop in Copenhagen to look at and learn more about a 18th c. pair of candlesticks in their window that were similar to some I had seen at Rosenborg Castle. The shop had wonderful things that I would love to own but a little out of my reach. After talking to the friendly owner for nearly a hour he said he had some medical things and opened a drawer..... and my eyes spotted this. I knew it look familiar... but it took till I rode home on my bike and checked it out. WOW... was I surprised.... it is a perfect match in both illustration and description for the caliper shown in Bergeron's Manual du Tourneur 2nd edition of 1816. This to my knowledge is THE FIRST ILLUSTRATION of a vernier caliper making this a very early example and wonderful addition to my collection!!!!!!!

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You can see the caliper listed as fig. 9.... here is a translation of Bergeron's text by Honrick.... he says it may not be perfect but I think he has the gist of it and I thank him for doing it. Yes I know it is long.... but that is the way the French write.... just skip this if you want to see more photos and restoration.....

Translation from Bergeron, Manuel Du Tourneur, 1816.
Volume II. Pages 8 - 11.
“Fig. 9 represents a kind of sliding compass, which we call Compass
Comparator.
It is formed of three blades of copper; two are fixed at A, on one of the heads
that has a point, leaving a space between them in which sits a third blade slightly
thinner than the other two, and the length of which is practiced with a groove in
the end we see at b.
At the other end of the inner blade is fixed the second head B, to which are
attached two copper cheeks, C, D, which slide along the outer blades and are
marked on both sides. The small bolt at the lower end of the blade holds the
inner blade, and therefore the head B, at the determined spacing. On both sides
of the compass are engraved the following measures: 1. “le pied de roi” (King’s
foot); 2. “le pied du Rhin” (Rhine foot); 3. English foot; 4. the circumference of
a circle whose diameter is known, calculated on the report of Archimedes, that is
to say to twenty-two.
We have followed the description of the compass before us, which has been
provided by a distinguished amateur, but we feel it would be easy to substitute
any other measure for the first three: for example, the metric foot instead of the
English foot, etc. We might also, for the fourth, use the report of 113 / 355 found
by Adrian Metius, which is more accurate than 7 / 22. [113 divided by 355
= 3.1415929 or pi.]
Both cheeks, C, D, have on their face a similar division of the vernier
graphometers [Vernier scale], and whose use is roughtly the same.
This division takes in nine lines of the measure marked on the corresponding
face, dividing it into ten equal parts. At the point where this division begins a
zero is marked lengthwise by a small bar. When this small bar is not located
just in front of a division line, it is found how many tenths of lines it is remote, by
counting the devisions of the vernier until one of its divisions coincide with those
of the rule.
The purpose of this instrument are quite numerous; it is:
1. To compare the three measures that are engraved. If, for example, we
want to know how much 3 inches 4 lines, “pied de roi,” equals in inches and
lines, “pied du Rhin,” we move the head B until the zero bar on the “pied de roi”
vernier scale is at 3 inches 4 lines. We turn the compass over, and we see that
the zero bar on the “pied du Rhin” vernier scale is at 3 inches, 5 lines, and 4
tenths of a line.
It would be the same if one wished to compare other measures marked on
the faces of the compas.
2. Calipers all pieces round, flat, or square. Simply grasp the piece between
the two steel heads and the zero indicator of any one of the measures will
indicte the thickness or diameter of the piece.
3. To measure the depth of a hollow piece, a rebate, or any ledge on a round
or straight piece. To do this the lower end of the inner blade is extended
downward, until it touches the bottom of the recess, and the outer frame is
lowered until it touches the upper edge of the piece. The zero indicators mark
the depth of the recess.
4. It indicates immediately and without error a tenth line for the circumference
of a circle whose diameter is known. For example, we want to know what is the
circumference of a circle whose diameter is 2 inches 7 lines, we place the zero
vernier indicator of the “pied de roi” at the division, and the vernier zero indicator,
corresponding to the division drawn on the same blade, indicates a
circumference of 8 inches, 1 line, 4 tenths of a line.

We observe here that the circumferences are calculated for diameters whose
dimensions are in parts of “le pied de roi.” If the given diameter was a factor of
“le pied du Rhin” or other measures, it would be necessary to first change it to
“pied de roi” inches and lines, and see the corresponding number on the
circumference scale, then we would know the result for the “pied du Rhin.”
These reductions are made by the instrument, and present no difficulty.
5. Finally a point about the methods of measuring just described, so as to be
able to use them as needed. This advantage is not the least of those that the
comparative compass provides, and the Amateur who wants to draw a machine,
or reduce it proportionately, will feel the full value.
But we will add here that the merit of this instrument depends entirely on the
accuracy of the divisions and the precision of its adjustment, and we would urge
those who procure this type of instrument to carefully check before using it.
The groove for the middle blade may be shaped like a rack. Then, through a
gear at the end of the frame the blade is moved forward or backward more easily.
This adjustment works well, however there are cases where the thickness of the
gear can interfere. Besides, the movement is a bit slow, and we believe the first
method is the preferred method, being simpler and requiring less time.
An instrument of this kind, which, instead of the different measures we have
described, is engraved with a single measure on each side, such as “le pied de
roi,” and the development of circumferences with a vernier indicating twentieths
of lines on one side and twenty fourths of lines on the other side, divisions easy
to distinguish with the naked eye, would be invaluable in the practice of the
sciences and the arts.”

You can see this is a perfect match... even to the scales on it...

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Now who made mine? I don't know.... it is engraved "H. Plőtz ou Copenhaguen"...... is this a maker or owner? There were not a lot of tool makers working in Copenhagen at that time, also if it was made in Copenhagen why didn't he use Danish or German ?(a language used at court sometimes) to describe the scales and then there is the spelling of Copenhaguen, this is a odd European spelling still sometimes used. But the engraving looks similar...... or is it? I would think a professional engraver would be able to space his letters out to get it on one line? Anyway what we can tell is this tool has been in Copenhagen for a very long time.
The more I think about it I feel it came from Bergeron's shop in Paris..... another little detail is the tools sold from that shop were almost never signed.

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Now mine was missing a screw...... but looking at the staining it looked more like a knob. I could figure out the size from the shadow it left.... but the engraving showed a wing nut???????

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I found this photo in Nessi's wonderful book Antique Tools & Instruments (if you like pretty photos of great early tools this is a must!) and it shows a similar caliper set into a drawing set.... with a knob!

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So I set about making a knob this morning.... it is always such fun to be making a part for some 200 year old thing with the research material being what the original maker would have used, in this case Bergeron's book.

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The thread was 1.8 mm, the knurl I had from my assortment, the style is based on the photo of the set above and the other knobs shown in the book....... the hardest part for me is aging it to look right. My dear friend the late Bob Baker was the master and I would just have him take care of this.... but since he is no longer he can't. I miss him dearly.

So how would darken the brass to add a couple hundred years? I just heated it which seems to speed up the natural oxidation process.

And for those that might worry, I signed and dated my knob on the underside should some future scholar not be confused.

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I never thought I would ever find one of these...... you just never know and if it is meant to be it will......
 
I've used cold gun-bluing to darken brass hardware. Birchwood-Casey's gun-blue can be found nearly anywhere that sell guns or ammo.

It darkens pretty quickly, but rubbing the dark stuff off with fingers, cloth or the no-grit scotch brite does a pretty fair imitation of the wear generated by handling. You might be able to get a lighter brown by diluting the solution, I haven't tried it.

Great find! Any thoughts on how long this design might have been common?
 
I just realized that I have a copy of a Bergeron catalog and price list dated 1817..... this is a very rare book and hence I only have a photocopy.... it priced pretty much everything in Manual du Tourneur using the plate number and descriptions........ we can see that this caliper cost 72 French Francs then....... wonder what that is worth today?

I do not know how long these were made but I would guess there never very many sold....

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Rivettt,
Very interesting .
Thanks for sharing your photos and knowledge about the caliper with us.
I’m glad to know it is in the hands of someone who appreciates it and can take care of it .
Regards,
Jim
 
yeah know
if you mount that on a nice oak board
you could probly get a few bucks on e-bay for that thing ;)
 
Rivett,

What an exciting find... !! You must have had to muster up a lot of self-restraint while being shown the caliper for the first time...:willy_nilly:

Awesome job on the knob... :cheers:

Brian
 
How is it calibrated? I notice the upper scale is divided into 1/12, with a 1/10 vernier. The lower scale is divided into 1/10, also with a 1/10 vernier. But the whole units used on the lower scale are slightly smaller than those on the upper scale.

How do those units compare with the US inch?
 
gbent Notice in the text the caliper was graduated in English (London), German (Rhine) and French (Paris) inches.... each of these is a little different in length hence the need for a comparative caliper. Somewhere here on the PM we discussed the different inches in Europe in detail. Basically that is one reason metric made so much sense if everybody used the same system......... and these different inches are not all divided by 16th the way we do ours.... some were 10ths, the French were 12ths and so on....

Sach... I did, I almost grabbed for it!.... funny thing is the room was pretty dark and I couldn't really see it well..... I couldn't even read the "Copenhaguen" with a loupe..... I asked the dealer if that is what it said and if he could read it..... he stated that if it did say that it would cost more and I replied maybe he shouldn't try reading it...... he was joking.

WP I still have that board!!!!! and a nice one it is....

Peter Your right.... but different stuff..... a month of shopping brought a rule, a hammer, a divider (but it is 17th c.) and this.... plus 9 candlesticks, some glasses and pottery.....

JimC You are welcome, and thank you for letting me know you enjoy these posts.
 
How is it calibrated? I notice the upper scale is divided into 1/12, with a 1/10 vernier. The lower scale is divided into 1/10, also with a 1/10 vernier. But the whole units used on the lower scale are slightly smaller than those on the upper scale.

How do those units compare with the US inch?

I wondered the same thing, so checked them out:

Pied du Rhin (Rhine foot) 333 mm - 13.11 inches
Pied de Londres (London foot) 312 mm - 12.28 inches
Pied du Roi (King's foot) 324.8 mm - 12.79 inches
English foot 304.8 mm - 12 inches

Must have been confusing if you travelled around much.

franco
 
NICE find!!!:drool5::drool5: Amazing that the basic form hasn't changed that much. I don't see a description of a use for the top jaws. They look like they could be used as trammels but not for inside measurements????
 
Jon You are right it could be used as a compass, I guess that is why they called it that which I had not really noticed. It is interesting to compare it to this one I also have,

http://www.practicalmachinist.com/v...ier-beam-compass-caliper-dated-1818-a-224980/

The 1816 as I'll call it seems so much more advanced and refined in it's design than the one dated 1818, but then as that thread explains it is really based on a much older design.... one thing is for sure, the artistic embellishments sure went away, new design must have come down from corporate?

"Must have been confusing if you travelled around much." .... oh no, just because you had different languages, currency, customs, weights & measures, waring tribes & clans, slow modes of transport (like walking) etc, etc, etc...... and people complain about travel today? But think of the rewards.... like this caliper I found..... and then I wonder what it was like when Mr. H. Plőtz brought his from Paris and showed it to his friends?...... could it have been like showing a I-phone to someone who had only seen a telegraph?
 
...and then I wonder what it was like when Mr. H. Plőtz brought his from Paris and showed it to his friends?...... could it have been like showing a I-phone to someone who had only seen a telegraph?

Probably something akin to the reaction I used to get from many sugar cane farmers in the mid 1970s after I switched from using a slide rule, itself unfamiliar to many farmers of the time, to a hand held battery operated calculator when estimating their crop tonnages. This modern marvel had four integer plus one decimal place capacity and a six digit LED display, and was about 5" x 3" x 1 1/2". They were amazed and somewhat disbelieving that something so compact could work so quickly and accurately.

franco
 
In trying to figure out what the value of this when it was new I came across these formulas. None are perfect for the years but might be close? I don't know, maybe someone else can have a try.

I came up with a French Franc might have been worth .193 cents to the dollar, a dollar had the spending power of $ 16.82 compared to today so.... .193 X 72 X 16.82 = $ 233.73.... which is about the same list price for a top of the line dial or digital caliper today??????

As for Mr H. Plőtz , we might have found him but are still checking...... seems he might have been Swedish.
 
The tale gets even better.....

A big thanks to my friend and student Kirsten who it appears has found our Mr. P.....

Yes, I did find some dates of H.Plötz.
His full name was Hugo Heinrich Edwin Plötz.
1880 lived he in Kopenhagen, Vesterbrogade 51, 2 floor left. his age ca. 48, unmarried,his occupation: mekanikus.
1885 lived he in Kopenhagen, Naboløs 6, 2 floor, his age ca. 50, unmarried, occupation: mekaniker, born in Sweden.
1890 lived same adress, his age ca. 54, unmarried, occupation: mekaniker, born i Stockholm.
This is all I can find in Denmark about him.

I think this might be our guy based his occupation... a mekaniker translates to a mechanic, a term often used in the 19th c. for a machinist.... he could NOT have been a car mechanic as there were no cars yet.

Two things about this are interesting....... his age, being born about 1832 puts him a little too young to have bought this caliper when it was new? or maybe not, I don't have a good date as to when Bergeron's shop closed it's store in Paris, I had thought it was in the early 1850's but a TATHS article states "In 1885 the Flotte (this is the name Bergeron's shop was known as, it's trade sign was three English ships, the full name was " La Flotte d'Angletrre") started to specialize in metalworking tools and slowly gave up making planes" This whole street was redone by Haussmann in the 3rd q. 19th c. The shop was located at 15 Rue de la Barillerie. this is in the center of the map right in the middle of the little island. It is on the long red line going from 1 o'clock to 7 o'clock. Rue de la Barillerie (barrel maker) was renamed Rue de la Palis de Justice...

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Now this seems a bit strange, even if it was still there would a company still produce a nearly 70 year old design? I don't think so. Could it have been left over old stock? Maybe.... don't we all wish to go into a shop and find new on the shelf antiques? Or did he have a father of the same name who owned it? Hugo is not a Swedish name, I think it is French, maybe his father was in Paris and named his son after a friend. Another reason thinking about why this must have been a used or older tool when it came into his hands is by the mid 19th century France was already making more, lets say modern styles of tools... think of the Palmer micrometer? So what was a guy doing with a comparative caliper a generation older than he was? and was so proud to own this he engraved his name on it?.... a lot of folks don't bother to sign their name on used tools.....

Now the other fun part of this story, assuming this is our guy. His address at Vesterbrogade 51, 2 floor left (left would be TV today, it would read Vester.... ,51, 2tv).... this road translates to Western Bridge Road which is the main road out of the old city to the west.... it has been there about 850 years. This is only a few blocks from where I stay when in town.... and on the morning I headed off to go to the shop that where I bought this caliper I stopped in front of his house, not knowing of course and had a hot dog while sitting on the stone wall around the tree you see in the square in front of Vesterborgade 51 which I think is the grey building to the right! This photo from Google seems to have been taken one of the rare times a hot dog cart is not sitting there.... for those that don't know Copenhagen and other cities in Northern Europe have hot dog carts all over town... it is their idea of fast food.... Paris has it's crepe wagons, Mexico and cities in the southern part US have tamale carts.......... so wonder if his ghost was somehow guiding me that day........ some ghostly guy looking out the window telling that American tool collector to go buy his caliper back???????? Next time I'm in town I'll have stop by that square for a visit.

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To me this is the fun part of collecting neat old tools...... putting them in someone's hands 100's of years ago.
 
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