Sunday, May 31, 2015
JR Newsletter: 31 May 2015 (243)
This week's JR Newsletter starts with a response to Winston Zack's inquiry from last week.
Dick Johnson wrote:
In answer to Winston's inquiry about sinking a design into a die and the kind of press used to do this.
Surprise! The press used to sink a device into a die is the same as one which could be used for striking coins.
The answer is the screw press. A very brief background of the screw press.. The first such press was developed 1st century BC to press grapes into wine. In 1506 an Italian engineer developed a screw press to blank lead sheets to make seals for the pope.
In the mid 1500s screw presses were in use in European mints. In 1652 John Hull obtains a screw press to strike his Pine Tree shillings in America. A collar and ejection mechanism is added to the screw press at the Bologna Mint by Francesco Camrlli in 1786.
Matthew Boulton, father of the private mint, and his partner James Watt add Watt's steam engine to their screw press enabling them to strike coins in quantity (instead of hand feeding).
In 1792 David Rittenhouse obtains a screw press for the Philadelphia Mint, and Adam Eckfelt builds additional screw presses biased on that first one. In 1851 the London Mint adapts a screw press just for their hubbing needs. In America the Philadelphia Mint acquires a screw press specially for hubbing in 1892.
Screw presses can be found in machine shops today for use in moderate pressing work.
I mentioned hubbing. The ancients knew of hubbing for use of copying dies as early as circa 530 BC. Because iron can be treated (by heating and rapid cooling) it can be hardened or softened at will. A hub would be hardened and pressed into a soften die blank by use of a screw press.
Now what the engravers did at the Philadelphia Mint was to engrave the device image only in the correct size. Some engravers like to work in the positive, having the image in front of the constantly, or carve the image negative. Hubbing changes polarity. You need a positive hub to make a negative die.
The device only was in this hub. All lettering, stars and dentiles forming the border were added individually by punches. Tap a punch (of hardened steel) into a soft iron die blank and it forms the image at the end of the punch.
This diesinking is tricky work as the position of the punch is critical. It must be in line (same base line) with other letters;. the distance from the proceeding letter is critical, as well as the rotation of the punch. Finally how hard the punch is tapped results how deep it sinks into the die (to become a raised letter when struck). This depth must be uniform for all lettering.
This method continued throughout the 19th century, at the Philadelphia Mint even though it had a die-engraving pantograph (the Contimin) in 1836, replaced by the Hill reducer in 1857. They obtained models from sculptors, made patterns from these first in iron, later in copper. The Mint used these machines for the device image only, preferring to add everything else by punches.
It was not until 1920 and de Francisci's Peace Dollar, did the Mint cut the entire image -- device and all -- on their Janvier pantograph. Victor Janvier developed his machine in France beginning in 1892 and pattend in 1999. Medallic Art Company imported the first Janvier to America in 1902 and sold one to the Philadelphia Mint in 1905.
Were it not for the Janvier die-engraving pantograph we might still be engraving dies by hand.
Winston can find pictures of screw presses on Google as well as Janvier pantographs.
Author, Editor, Senior Consultant
Cofounder - Signature Art Medals
Corporate Historian - Medallic Art Company
And speaking of Winston Zack…
Congrats Bob Feldman on being the first reported person to reach 123/123 known capped bust dime die marriages. I'm sure there will be many more congrats coming your way. Certainly your accomplishment underscores the difficulty to reach such a goal. On average you added 2.5 new die marriages every month!
We all look forward to seeing you upgrading your set in the future. Not to mention, at the rate you acquired your capped bust set, you should be able to acquire all 30 draped bust dime die marriages by this time next year! And if you can do that primarily from eBay that will be all that more impressive!
David Quint also wrote with his congratulations for Bob Feldman and other comments:
An excellent JR Newsletter last week IMHO. The Finkelstein article on early mint operations is excellent, I can't wait for the future installments. The best thing I have on early mint operations is the Taxay book on the US Mint and Coinage, which is quite detailed but hasn't been update for 50 years. The book does go into some detail as to how working dies were punched by "gravers" which Winston Zack will find helpful in answering his questions (the letters and stars were punched by hand, not machine).
I am blown away that Bob Feldman has built a complete set of capped bust dimes (including the R-8 1827 JR-14), and that he did it in only 4 years. In the last dime census, we had 8 collections of 122 coins, and there has never been a set of all 123 (Bob's capped dime collection was not even included in the last census due to a communications issue). This is really quite a feat and an event in the world of capped bust dimes. Congratulations to Bob!
I've attached a recent study I did of the 1798 JR-4 obverse die states. This variety exhibits a spectacular series of prominent die cracks that traverse much of the right obverse field (the JR-4 was the only use of this obverse die). I found all of the pics on the Heritage site.
Editor: David's study of 1798 JR-4 obverse die states is linked here: http://www.docstoc.com/docs/173893104/1798%20JR-4%20Obverse%20Die%20State%20Progression.pdf
Finally, Peter Mosiondz, Jr. wrote with some book offerings:
The Early Coins of America, Sylvester Crosby. 1983 Quarterman reprint. HB. DJ protected in Brodart Mylar®. New. $25.00
United States Copper Cents 1816-1857, Howard R. Newcomb. 284 pp. 11 plates. HB. DJ protected in Mylar®. New. $25.00
Illegal Tender: Gold, Greed and the Mystery of the Lost 1933 Double Eagle, David Tripp. SB. New. $15.00
Million Dollar Nickels: Mysteries of the Illicit 1913 Liberty Head Nickels Revealed, Paul Montgomery, Mark Borckardt and Ray Knight. HB. DJ protected in Mylar®. New. $20.00
Add $3.00 Media Mail Postage
Peter Mosiondz, Jr. JRCS #867
26 Cameron Circle
Laurel Springs, NJ 08021-4861