18th Century Screw Press Efficiency at the U.S. Mint
brianc1959
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My apologies if this has been discussed at length before - I couldn't find what I was curious about after a quick search.
I'm curious about how long it took to make a coin using one of the old screw presses in the 18th century. Just thinking about it makes me tired! On a related note, how many screw presses were set up in a production line for a really high-volume coin like the 1794 cent. I assume that numerous die pairs may have been used simultaneously on different machines. Also, how many employees manned the presses, and what sort of working hours per day, etc..
TIA
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Interesting question.
I admit I haven't really thought about it.
Interesting question. Is there a book that explains the early mint and these processes?
I miss @RogerB .
"If I say something in the woods and my wife isn't there to hear it.....am I still wrong?"
My Washington Quarter Registry set...in progress
https://thevintagenews.com/2016/03/03/the-early-modern-period-striking-coins-with-a-screw-press/
I am sure RogerB has the answer...and maybe in his book Mine to Mint...or one of the others. Cheers, RickO
Thanks for the link. Blanks can be struck at a rate of one every two seconds, 30 per minute is pretty impressive given the mechanical size and movement of everything. A team would have to work hard and steady.
"Workmen and Labourers:
1. The time of work and labour in the Mint, shall be understood by all employed therein, shall be eleven hours each day...
2. Every workman and labourer shall attend, in the morning, after breakfast, and after dinner, at the stated hour, at which time the bell of the Mint shall be rung, and in case one shall be absent himself fifteen minutes thereafter, he shall forfeit a sum equal to his wages the rest of the day, but if anyone shall repeat such forfeitures more than twice in one week, he shall be reported to the director by the assistant to the chief coiner, or the foreman of the Mint, as a person undeserving of employment.
11. The pressmen who shall have the keys to the presses, shall never leave them without locking them with the chains, so as to prevent the levers from being moved, and when the business of the day is finished, shall immediately deliver the keys to the chief coiner, or other superior of the department as may be directed - if any pressman shall neglect this order, he shall be immediately discharged and forfeit all his wages then due."
Source: Orders and Directions for Conducting the Mint of the United States, Established by Elias Boudinot, Director of said Mint. November 2, 1795. Philadelphia: Printed by John Fenno, No. 119 Chesnut Street, 1796.
Pressmen employed by the Mint, October, 1795:
Chief Pressman, John Schreiner, $1.80 per day wage
Pressmen, Christopher Baum, John Keyser, Frederick Bauck, $1.00 per day wage
The Chief Coiner has a minimum of "Two Pressmen" which assumes two Pressmen swinging the levers of the screw press. Until feeding and ejecting mechanisms were developed, a person would also be needed for that operation.
The best articles on US Mint screw presses were written by Craig Sholley for Penny-Wise and John Reich Journal, these are on the NNP.
There have also been studies by EAC on striking rates, I can't recall exactly the calculations, but I believe it was slower than stated in the linked article (2 seconds each). Regardless, they are estimates.
In 1794, the US Mint did not have a large screw press, it was in work and would not be completed until early 1795. By 1802, the Mint had five screw presses. In 1794, I would expect one press in operation and by 1795 at least two screw presses to strike copper, silver, and gold denominations. Half dimes could be struck on a smaller press.
Extremely interesting information - thanks! I'm surprised so few presses were used, and it sounds like very demanding work. Also interesting that the pressmen earned the same wage ($1.00 per day) my grandfather earned as a ditchdigger in depression-era Mississippi. Wonder if they got paid in silver dollars during 1794?
@brianc1959 asked:
The early US Mint did not have a bullion account and all silver and gold coinage was returned to depositors who were individuals and banks. Payment was made from an arrangement with the Treasury Department and the Bank of US (the Mint was then State dept):
"The Account of the Mint [1795]:
Salaries of Officers and Clerks of the Mint
Wages of Labourers...
All accounts against the Mint for work done, materials found, or services performed (excepting the commissioned officers of the Mint) must be exhibited to the proper clerk on the last day of the month by 12 o'clock at noon except the same will happen on a Sunday and then on a previous day, or they will be postponed. Payment will be made on the next working day at 12 o'clock, and at no other time, special cases of persons living at a distance excepted."
edit - the Mint workers would not have been paid in silver dollars in 1794 from the one small mintage, but from the larger dollar mintage in 1795, workers could have obtained silver dollars from the Bank of the US. I would expect some workers did want a shiny new 1795 silver dollar!
Here is a description of a screw press (coining engine or mill) that is from my collection of rare literature, which was printed in Philadelphia on March 10, 1792, just prior to the start of the US Mint from the Coinage Act of 1792. The first couple of sentences describe the rimming (Castiang) machine. Chief Coiner Henry Voigt was the only Mint officer or worker who had a few years experience with coining at a mint. They relied on his experience and mechanical expertise, along with some illustrations and descriptions of screw presses. The US Mint officials did read this, as they were subscribers. One important component of the press is the "square box" which transfers the rotational force of the screw into a strictly vertical force upon the "dyes."
It describes a screw press as capable of 20,000 coins per day. For eleven hours, that would be about one coin every two seconds, but it may have been a longer day or two working shifts. There was also downtime to consider.
"The planchet is laid flat on the square of the effigy. which is dormant;"
That statement describes the obverse die as the anvil die, as "effigy" in numismatic terms is a portrait. For some early US denominations, it thought that the hammer die is the reverse die, and the anvil die is the obverse. Chris Pilliod had evidence for this in a JRJ article.
Was this the usual die setup for later US coins? Also, were British coins generally struck with the obverse as the anvil die?
Just wondering if this was the die setup by tradition, or some other reason.
30 per minute might be peak speed, but not sustainable over the whole shift.. anyone who's worked an assembly line knows that it slows and stops periodically.
An average might be 20 or 15 coins per minute, but some times a thing breaks bad or the workers suck or bail altogether.. and output would reflect the issues.
Liberty: Parent of Science & Industry
PM sent
Perhaps it was convenience. I'm thinking that the dated ſide may have been ſelected to be the hammer die ſo that the anvil could be left in the preſs as long as needed in caſe it was more difficult to change. Pure ſpeculation on my part. Another poſſibility is so that the preſs operators always ſaw that the monarch was watching them.
(Spell-check is aware of 'ſ' being an 's', by the way. Learned ſomething new today.)
Keeper of the VAM Catalog • Professional Coin Imaging • Prime Number Set • World Coins in Early America • British Trade Dollars • Variety Attribution
Here's a picture identified as a 17th or 18th century mint. I think I've seen it at the ANA in their mini mint, as well. The person sitting in the pit placing and planchets and removing coins is a child, as they have the best eyes and reflexes for the work, best enabling them to retain the fingers needed to complete their shift.
Keeper of the VAM Catalog • Professional Coin Imaging • Prime Number Set • World Coins in Early America • British Trade Dollars • Variety Attribution
An update after I re-read the JRJ Sholley articles. In 1794-1800 "the records indicate that the Mint could operate two presses at a time." The limiting factor was the number of pressmen, and Sholley states the original presses were replaced by five screw presses by 1795 (JRJ January 2004).