The+Philadelphia+Mint

**__The Philadelphia Mint: Four Stages in the Development of Mass Production__**


 * Introduction**

Mints have been around for thousands of years allowing societies to run an economy based on solid currency. While the main function of coins is to grease the wheels of the economy, they have many other purposes. Coins can be used to unify a nation, such as when the United States moved past the Articles of Confederation to the Constitution used to day. Under the Articles, each state had its own currency. This made trade and travel difficult through the newly formed nation. The Constitution allowed for a unified currency for a unified nation. Also coins are indicators of what a government found important to relay to its people. On US currency, words like “liberty” and “In God we trust” can be found with pictures of the Lincoln Memorial and the eagle. In unstable times, rulers would attempt to legitimize their authority by putting their faces on the coins. For example, Quietus was ruler of one part of the Roman Empire in 260 CE for one year and his image is found on two coins. The truly interesting part about coins is the way they are made and the fact that the process has not changed much since the times of Quietus, only the technology surrounding it has changed. We will explore this concept by looking at the Philadelphia Mint.

**The First Mint - 1792 to 1833**

The first Philadelphia Mint was officially built in 1792 and has the privilege of being among the first buildings to ever be constructed by the federal government, (Gilkes). At the time, the location for the building was very practical considering Philadelphia was the nation’s capital. It was unlikely that this city would remain in such a prominent role, but Philadelphia was also the headquarters to the Bank of the United States and was just an all around thriving center for commerce, (Wright). In 1793, production of 11,178 copper cents was successfully completed for the first time under the watchful eyes of mint director David Rittenhouse, (The United States Mint). In terms of methods of production, the first mint was extremely limited with the ways it could manufacture coinage and had to rely on relatively primitive forms of production in order to be able to produce the needed coins.

Observed in the First Philadelphia Mint was a severe lack of “power” by which the necessary coins could be produced. In fact, the two main forms of power were derived physically from horses and simple manpower, (Gilkes). Alternative forms of power would not come until later years when the Mint would have upgraded its equipment to include steam presses and other much more mechanically advanced equipment. Choosing its location in Philadelphia was another factor of why the first Mint had this lack of energy sources. At the time, water power was a relatively viable source from which energy could be derived and translated into mechanical work. Unfortunately for the Mint, the location in Philadelphia had very little to offer in terms of water power, and therefore the designs could not incorporate any of the advantages that this energy source could have potentially offered, (Wright). With all that said, a great deal was accomplished using the sources which were readily available. Manpower was used to drive small scale screw presses and mechanical work from horses was used to drive larger and heavier bellows.

Originally, the operations required to produce coinage at the First Philadelphia Mint involved a three step process through which metal is essentially taken from a raw material and turned into an acceptable, though often times crude, form of currency. The first step in making currency at this point in time involved heating the metals into a state in which they were pliable and able to be flattened into sheets. Using horses to run this heavy machinery, the heated metals were repeatedly put through rollers that would flatten the material into long ribbons, which were then processed into flat sheets called planchets, (The United States Mint). Next, the dies needed to be created from which the coins would essentially be “stamped” out. These dies were made manually by annealing steel into the proper configurations. Also, the designs that would be used to punch out the coins would all have to be carved and engraved by hand. Finally, once the sheets and dies were made, the manual process of stamping the coin shapes out would begin. All in all, this would very often create imperfect coins but at the time were still considered acceptable to be used as currency in this nation. On June 24, 1816, the first truly mechanized form of work arrived at the first Philadelphia mint, the steam press, (Gilkes). This innovation would allow the mint to progress from these original pain-staking tasks of striking coins by use of manpower and horse power. Further use of steam presses were incorporated in future Mints, (Steam Powered Coining Press).

**The Second Mint - 1833 to 1901**

The Second Philadelphia Mint opened in January 1833. The new mint was deemed necessary to produce coins for an ever growing national demand of a standardize currency. For the first three years, the operations at the second mint continued exactly as they had at the first mint only on a larger scale. In 1836, the French revolutionized the die making process. The adoption of this process saw the first marked change in the operations of the mint.

The French portrait lathe was in effect a three dimensional copier, (Roberts). Instead of hand engraving a die to press coins out of steel, these dies were first made in a wooden blank. The portrait lathe then traced over the wooden blank, now called a hub, and transferred the image into wood hub to be used for casting the die. This process allowed for the coin dies to be created much faster than before; a new coin could be turned out in weeks instead of months. This also allowed for a master hub to be used for multiple years as the final die could have the year etched into while still being copied from the same master die. This system allowed for the switch between coin years to be nearly seamless.

The portrait lathe was used until 1868 when the Hill reducing lathe was installed, (Roberts). The new lathe used a process very similar to the portrait lathe with one key difference. The Hill lathe allowed for the master hub to be carved out of a very large blank. This allowed for far greater details to be incorporated into a master die and then transferred into the much smaller coin sized die. This allowed for very complex coin designs to be used, as well as, a large reduction in defects in the smaller hubs.

Aside from improvements in coin designs the second mint saw the introduction of several other accuracy improving technologies. The second mint introduced new methods of assaying the gold and silver to be cast into ingots for the stamping process, (Androulakis). At the first mint, gold samples were taken at random and the results were applied to the entire batch. This allowed for many defects and inaccuracies with the gold processing. At the second mint, the entire batch was melted down to homogenize the gold and then a sample was taken. This allowed for far greater accuracy in the processing of the gold into coins. The second most important improvement in processing technique was the introduction of the metric system over the British Imperial system (Androulakis). This permitted for simpler math due to the base ten standard versus the base sixteen standard. In essence, fractions where completely removed from the calculations, which greatly reduced errors in an age without calculators.

Not only were improvements made into the mental labor needed to process coins but huge improvements were made in physical labor too. The second mint saw the introduction of steam engines for the pressing of coins, forming of gold and silver ingots, and the extrusion of the ingots into sheets of metal for pressing, (Philadelphia Mint Tour). The steam pressing allowed for much greater pressure to be exerted onto the metal coin blanks, allowing for a more complete transfer of the image onto the coin and cut down the amount of rejected coins, (Landis). The second improvement in physical labor was the process of using metal alloys, (U.S. Treasury). The alloys allowed for the design to be stamped into a metal that is malleable enough to be stamped but stable enough to hold the image for a long period of time and abuse. This allowed for less pressure to be exerted on the metal and allowed for coins to stay in circulation much longer.

**The Third Mint - 1901 to 1969**

The third of the four mints was opened on June 13, 1901 at the new location on Spring Garden Street. The mint was designed by a group of architects headed by James Taylor. The new location was picked because it was close to smelting facilities, which would be more convenient then previous mints, (Roberts). The last two mints had been very successful and to ensure that the new mint would continue to produce quality coins as well as the ability to produce them in a larger quantity the new mint was larger and had been updated with the new machinery. The new mint would set the bar for all other mints to strive towards. It was said at the completion ceremonies that “No pains have been spared to provide this mint with the best machinery to be had, and…it will be…a model institution.” (Androulakis).

One of the most important new machines was introduced in 1907. It was the Janvier Reducing lathe, (Roberts). The Janvier lathe would replace older models because it took less time to create master hubs. These hubs could still be reused to make master dies for years since the Janvier lathe only printed the first two digits of the date on the hubs leaving the last two digits to be printed only on the dies with each new year. By incorporating a technology which was already used in some lathes and adding speed the Janvier Reducing lathe increased production and quickly replaced older lathes.

Until World War II all coining was done in gold, silver, nickel, and alloys of them. As the war progressed the need for these precious metals was so great that the mint had to change the composition of its coins to mostly zinc, copper, and nickel, (U.S. Treasury). Copper even became so valuable for ammunition that the penny was stuck in steel coated with zinc in 1943. Once the war had ended most modern coins were beginning to be produced. Many of these coins have seen very few changes since this time.

The third mint would stop its production of coins in 1969, but during its era it was the one of the leading mints of the world producing much of the coins for the United States as well as many different forms of foreign currency.

**The Fourth Mint - 1969 to present**

The fourth Philadelphia mint was opened in 1969 only two blocks from the site of the original mint. The basic techniques for making coins there remain the same as they were in 1792. The primary difference is the emphasis on automation and more efficient power generation and distribution. These changes led to a much higher output and quality of coins, with the mint’s production at 1,721,220,000 for regular circulation coins in 2009, (The United States Mint). This figure does not include the commemorative coins produced there, nor does it include the dies produced, since the Philadelphia mint produces dies for the other U.S. mints as well as for its own operations.

One of the main changes in terms of energy production was the transition from wood to gas furnaces for use in the heating of the metal which is used to make the coins, (Landis). This allowed the heating process to be much more controlled through the use of several smaller burners. Because of this, the metal could be kept on conveyors, allowing each piece to be heated evenly. In addition, this reduces the risk of oxidation. At the end of this process the metal is quenched to preserve softness and then dried using high powered jets of hot air, (Mints and Minting).

The quality control process, before and after coin production, has also been greatly expedited by mass inspection systems. Originally, the planchets used to make coins were hand sorted to check for defects. In the system of the current mint a series of screens is used to insure that flawed planchets fall away before they are used to make coins, (Mints and Minting). Once finished, the coins used to be checked with magnifying glasses to insure that there were no defective ones. As of 1996, the system was revamped with sensors that reject flawed coins as well as screens, or riddlers, that detect improperly sized coins. Although it is no longer the primary inspection tool, magnifying glasses are still used by operators as a further level of quality control.

These and the automation of other processes of the mint in its fourth incarnation have led to heightened production compared to the previous facilities.

Works Cited

Androulakis, Yiannis. "Making Coin Blanks and Planchets." //Fleur De Coin - Greek Modern Coins and the Euro Currency//. 2010. Web. 10 Feb. 2010. . Gilkes, Paul. "History of the U.S. Mint." //Coin World//. 2010. Web. 10 Mar. 2010. . Landis, John H. "Coins." //The Encyclopedia Americana//. 1918. Print. "Mints and Minting." //PCGS Coin Guide//. Collectors Universe Inc., 2010. Web. 11 Feb. 2010. . //Philadelphia Mint Tour//. Philadelphia Mint, Philadelphia. 14 Feb. 2010. Performance. Roberts, Gilroy, and Don Taxay. //The United States Mint and Coinage//. New York: Arco Pub., 1966. Print. //Steam Powered Coining Press//. The Franklin Institute, Philadelphia. 14 Feb. 2010. Performance. "The United States Mint." //The United States Mint Home//. The U.S. Department of the Treasury, 2010. Web. 10 Feb. 2010. . "U.S. Treasury - FAQs: Production & Circulation of Coins." //United States - Department of The Treasury - Homepage.// The U.S. Department of the Treasury, 2010. Web. 11 Feb. 2010. . Wright, Robert E. //The First Wall Street: Chestnut Street, Philadelphia, and the Birth of American Finance//. Chicago: University of Chicago, 2005. Print.