Author Topic: Earlier Date For Machined Cut Letters 1817  (Read 1787 times)

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Offline constanius

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Earlier Date For Machined Cut Letters 1817
« on: May 04, 2014, 01:21:04 AM »
"The first coin/medal engraving machine was the Belgium Hulot of 1766. This machine had peddle power and was followed by minor improvements by Frenchmen Mercklein (1767) and Dupeyrat (ca 1788).

Dupeyrat sold one of his pedal-powered die-engraving pantographs to Matthew Bolton's Soho Mint in 1789.  James Watt replaced the pedal-power with steam-power.  It was utilized there to do what it did in other mints – reducing the main device from an oversize metal pattern, then employed hand engravers to add lettering and small symbols by hand punches.

Boulton expressed the wish in 1797, “I look to the time when it can cut the entire side of a coin or medal, not just the device.” This was not to happen until Victor Janvier invented his die engraver in 1899."


Unfortunately the last sentence seems to be incorrect, even though it is the accepted version.  Why do I think that?  Well I think I have solid proof that the letters on a medal were machine cut with the rest of the medal as early as 1817, not only the letters but the denticles too.

This medal, BHM#944 Death Princess Charlotte 1817 by Kempson & Sons, 26mm Rare silvered AE, clearly has machined copy/reducing lines that travel unbroken across both the field, letters & denticles.



These can clearly be seen running through the 'C' and the denticle above the upper 'S' in the enlargement below


« Last Edit: July 10, 2017, 01:43:44 AM by constanius »

Pat

Offline Figleaf

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Re: Earlier Date For Machined Cut Letters 1817
« Reply #1 on: May 04, 2014, 01:24:04 PM »
Neat! Got to digest this. Some questions in my mind (I don't expect too many answers).

Are they really pantograph impressions on the die? If so, why are they so much less clear on the other side? Could the date be wrong, in the sense that the silvered issue came later? Surely not 80 years later. What stopped people from using the pantograph for letters (dates, I can imagine). Even in modern times, there is evidence that device and lettering were sometimes coming from different sources (see recent discussion on "double die" US cent 1955) Kempson was a prolific maker of medals. Could he have invented something to solve that problem, considering it a trade secret, so that it died with him?

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline constanius

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Re: Earlier Date For Machined Cut Letters 1817
« Reply #2 on: May 04, 2014, 03:59:22 PM »
Thanks for the interest Peter.  Here are a few other pictures which might help with answers.

The first is a brass example of the same medal showing machine marks.









Queen Charlotte Death Medals 1818 RRR. BHM #968
Obv.   Diademed head of Queen Charlotte, right. H . M . G . M . QUEEN CHARLOTTE.
Rev.   BORN MAY 19 . 1744 / MARRIED / SEPR. 9 . 1761 . / DIED AT KEW / NOVR. 17 . 1818 / AFTER A VIRTUOUS / REIGN WITH HER / BELOVED KING / OF 57 YEARS
AE, AE silvered 25 by ? AE RRR; AE silvered RRR. Unlisted in Brass.

Shows that the copying machine could not engraver the centre of the medal, looks like the 'U' in Queen might have lines, that might be wishful thinking but not when you see the following picture.




This picture shows some hand-engraving done to the centre of the die after the the above medal was struck and also some of the copy/reducing lines have been removed by some sort of polishing.......but most importantly shows very clear lines across the letters...., I assume the medal above it has had the lines on the letters worn down by handling.

Now there is some doubt as to whether this is by Kettle or an unknown medalist but seeing as all the other Kettle medals used hand punched letters into the Victorian era I now think it was issued by Kempson & your idea that it was a trade secret that he carried to his grave could be correct.  The fact that Kempson issued medals for Princess Charlotte's death in 1817 & Kettle did not, that Kempson issued medals for Queen Charlotte's death 1818 and that both these medals have lines across the letters and I have found no medal that is definitely by Kettle with these lines seems too much of a coincidence.  I need to put my thinking cap on!

Comparing the letter in 'Charlotte'  they look to be the same style so it appears even more likely they were both issued by Kempson.
« Last Edit: July 10, 2017, 01:54:09 AM by constanius »

Pat

Offline constanius

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Re: Earlier Date For Machined Cut Letters 1817
« Reply #3 on: May 04, 2014, 04:13:27 PM »
As to the confusion over Queen Charlotte's medal,  Brown lists BHM#964 & 968 with exactly the same description but which is which?.



Queen Charlotte Death Medals 1818 RRR. BHM # 964 & #968 but which is which no one really knows for sure.  Brown did not show pictures of either but he states #964 was by Kettle and #968 he states by unknown!!! but they are so similar they surely are by the same company, that being Kempson
Obv. Diademed head of Queen Charlotte, right. H . M . G . M . QUEEN CHARLOTTE
Rev. BORN MAY 19 . 1744 / MARRIED / SEPR. 9 . 1761 . / DIED AT KEW / NOVR. 17 . 1818 / AFTER A VIRTUOUS / REIGN WITH HER / BELOVED KING / OF 57 YEARS

Rechecked Brown #964 AE R; AE silvered RR; Br; N   #968 AE RRR;  AE silvered RRR. so the brass one is BHM#964 & the AE silvered is BHM#968 but  I think both are by Kempson.


« Last Edit: July 10, 2017, 02:16:06 AM by constanius »

Pat

Offline constanius

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Re: Earlier Date For Machined Cut Letters 1817
« Reply #4 on: May 04, 2014, 05:31:37 PM »
One from 1801 by Kettle showing the turning point & copy/reducing lines and the inability of the early machine to cut the centre of the medal, which had to be finished by hand.



A compilation of 3 examples. 



Thanks to Philip Atwood & the British Museum for the pictures of their 2 bras examples of this obverse, which show the further work done to the die with copy/reducing lines. The cheeks have been further engraved & the rear of what appeared to be part of the neck morphs into the lower part of the ribbon. There is also more detail in the hair & the upper part of the ribbon. Also the missing parts of the 'E's have been added. In the far right example the pronounced seperation between cheek, jaw & chin has been totally lost. Oh, and the copy/reducing lines have disappeared!
« Last Edit: July 10, 2017, 02:03:36 AM by constanius »

Pat

Offline Figleaf

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Re: Earlier Date For Machined Cut Letters 1817
« Reply #5 on: May 06, 2014, 12:53:26 AM »
Pure speculation, but here goes.

Why couldn't the pantograph do the centre? The Archimedes problem. You need a fixed point to move the earth and to hold the die being engraved. If so, that may be a clue to why the letters were done separately: elasticity in the pantograph's engraving arm. The further away you are from the centre, that holds the arm, the more pressure is needed to compensate for the flexibility in the arm. If you cannot vary the pressure on the arm mechanically, the outer parts will lose detail. The simple solution is to do the letters separately, with more pressure on the arm. The problem with this speculation is that you can reduce flexibility by making the arm thicker. Maybe the weight of the arm interfered with the speed of its movement?

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.