Pantograph, Die-engraving Pantograph. A machine for reducing three-dimensional bas-relief designs while simultaneously cutting a steel die. The mechanical engraving machine, which was early called a and later called a among other names, eliminates the requirement of manual labor to meticulously cut dies by hand engraving. It had the further advantages that many dies could be cut from one pattern, more than one size die could be reduced from the same pattern, the pattern could be seen complete before being placed into production of diecutting, and the ease of which design errors could be corrected.

The use of the pantograph in early mints – like the use of the collar, certain other blanking and striking techniques – was part of the mystique of coin making. As such, it was part of the technology closely guarded by mint personnel. To safeguard against coin counterfeiting early on the knowledge of the pantograph was not revealed to a general public (in England or America, but was published as coining technology in France and Germany).

At first the die-engraving pantograph was employed only to cut the main device of a coin or medal design – primarily the portrait and called a reduction punch – where lettering, dates and additional ornamentation was added by punches and hand engraving afterwards. With improved development of its mechanics, later die-engraving pantographs (those of the 20th century) could reproduce the entire design, cutting a finished die, lettering and all, from a complete pattern.

The machine requires an oversized model as the source of the three-dimensional design – a pattern or master. This must be in hard material (or at least have a hard surface) because a (tracing stylus) must ride over this surface. Early masters were cast or carved in metal (iron, bronze, brass) even cut in stone.

Early patterns of cast iron were made in both England and America for both coin and medal dies. As such it bore a more rounded detail lacking sharp, crisp edges. Metal casting lacks such edges because of (where metal does not flow into crevices of the model). Also important was the investment use for the casting. If this was wet sand the surface was not always smooth. An iron cast had to be worked afterwards to smooth all surfaces and sharpen all edges of detail.

In the 1850s had developed whereby a hard medal pattern could be electrolytically cast in copper or nickel from a model made of wax, clay, plasteline, plaster, wood or other composition. These electrogalvanic casts – called galvanos – proved excellent for the patterns used in mechanical engravers and replaced earlier iron patterns.

Not only were galvanos easy to make but even more reason for their fidelity to the original model in hard metal surface. Also steel tracing points as a stylus, could easily track the copper surface (even without a lubricant). The cutting point was shaped so that it had two cutting surfaces that made two cuts with each revolution (see illustration).

A steel die block of proper size and trueness is planed to have a smooth face; it is heat treated, annealed, until it is dead soft. This is mounted in the mechanical engraver to be cut into the die. Early reducing machines had a fixed cutter, later ones employed rotating cutters. The (tracing the relief on the pattern) and the (drilling into the steel) are both mounted on a long bar, pivoted at one end, which transfers the position, degree and depth to be cut into the die block.

The stylus (tracing stylus or tracing point) starts at the center of the pattern, and the cutting point starts at the center of the steel block, both progressing simultaneously outward towards the edge of the design. The tracer plays across the pattern’s bas-relief surface from center outwards on most mechanical engravers (only one pantograph [Keller] starts at the edge and transverses inwards – like a phonograph player).

Dies cut on early pantographs, or later by unskilled operators, often exhibited the trail of the cutting tool on the surface of the die. These lines require removal in the die by smoothing the surface, by BURNISHING or CHASING, a REWORKING of the die. If not they will obviously show on all struck pieces. While such concentric circles are not a diagnostic of cast iron models they were prevalent during the period such iron models were used.

The mechanics of the die-engraving pantograph are such that it can cut either incise relief or raised relief (as hubs or finished objects). The modern machines can even regulate the height of the relief, or, amazingly, reverse polarity (a right-facing portrait can be changed to a left-facing portrait). It can also change or add a die camber (shape of the table or background). Further, it can even enlarge as well as reduce a design!

In addition to these mechanical techniques is a seldom-used technique, these machines can, in effect, become a reproducing machine. They can cut a design into a composition that cannot be stamped, as ivory, bone or plastic.

The most modern medallic engraver was developed by a Frenchman, Victor Janvier (1851-1911), and his Janvier reducing machine became the premier die-engraving pantographs of the 20th century. The earliest instruments were merely copying lathes or cameo cutters, but the remarkable contrivance has been called a wide variety of names over the years: medallion engraver or lathe, portrait lathe, transfer lathe, reducing machine or lathe, diesinking machine, mechanical engraver, pantographic reducer, medal reducing lathe, medal and cameo reducing and engraving lathe, and, finally, by their maker's name (as Hill, Contamin, or the famed Janvier).

The products which can be created from dies made by this method are not limited to coins, medals and cameos in all, but also anything Any small object struck in a press from dies, as buttons, emblems, jewelry items, small parts and such, even tableware utensils could be coined. (It was not surprising that the tableware industry early embraced the Janvier and acquired more of these machines than any other industry.)

But what was so astonishing was the mint officials of the world who had to create high quality coin dies beating a path to the door of Janvier's small Paris factory. In the early 20th century if modern mints wanted quality diecutting and the highest fidelity coin reductions they needed a Janvier engraving machine.

History of the Die-engraving Pantograph

Existing records of the earliest known machines which reproduce three-dimensional images were either copying machines or virtual cameo-cutting lathes. These existed in England, Europe and Russia. They could reproduce a design in metal, but nothing as hard as steel.

The first true die-engraving pantographs were developed independently in France and the Low Lands. They not only had a bar affixed to a fulcrum, which provided the required reduction, but also the ability to cut into steel. These included the Hulot (no other name recorded) whose machine appeared in Belgium in 1766. This early reducing lathe was to have an influence on others who built improved pantographs in a number of countries. One of Hulot's machines still exists in a Brussells museum today as tacit testimony to this early creation.

In France, Saxton Merchlein, a machinery inventor, developed his reducing machine in 1767; while contemporary with the Hulot, each was developed independent of the other. Merchlein's machine was perhaps the first to be used for engraving coin dies at a mint, the Paris Mint.

Privately in France, Jean Baptiste Barthelemy Dupeyrat (1759-1834), a young mechanic, had developed a reducing lathe that attracted the attention of Matthew Boulton. Boulton obtained one of Dupeyrat's lathes in 1790 for his Soho Mint in Birmingham.

Obviously national mints in both France and England became interested in these machines, leading to a second generation of improvements. However, it was the private industry in both these countries that were to do the most to advance the mechanical engraver. Engineering developments in private industry were quickly assimilated in the equipment of national mints; but the technology did not flow in the opposite direction.

New ideas developed in national mints became closely guarded secrets. Advancement in the field – particularly for medals – had to come from private mechanical engineers working independently outside any national mint.

Second generation machines were built by Belgium medallist Joseph Pierre Braemt (1796-1864) in 1824 (undoubtedly based on the Hulot machine of his countryman). Braemt's machine still exists in the Brussells Mint Museum. Also the Hulot machine inspired one developed by Benjamin Cheverton, a British machinist in 1826.

In addition to the private Soho Mint, Dupeyrat's machines were sold to the British Royal Mint, in 1819, to the Karlsrue Mint in Germany, and other European mints about the same time. When James Watt, Boulton's partner in the Soho Mint, retired in 1804 he worked on improving the Dupeyrat lathe, continuing his endeavors until his death in 1819.

In France in 1820 an ingenuous machinist Ambrose Wohlgemuth built a "medal and cameo reducing and engraving lathe." He used modern principles of reduction but still employed pedal power, as had all previous machines. His lathe still exists and is in the Conservatoire des Arts et Metier, Paris.

A decade later in Beasancon France, a surgeon who took up sculpture, Jean Baptiste Maire (1787-1859) developed his own reducing machine after creating his first medals in 1834. Perhaps it was used by the Paris Mint since it is in the Conservatoire des Arts et Meitiers alongside Wohlgemuth's machine.

All first and second generation reducers had a fixed cutter; the work rotated while the cutting point was fixed to the bar. This was a true lathe. Third generation reducers employed the rotating cutting point; in effect transforming the medallic pantograph into a

France's Contamin (again, no other name known, and his dates unknown) working in Paris created an improved machine with a rotating cutter, called a This success led to widespread use of his machine. Probably developed prior to 1834, when Franklin Peale observed it that year. In 1836 Peale obtained the Contamin engraver for the United States Mint at Philadelphia. While not associated with the Paris Mint, Contamin was able to offer his machine to any buyer in any country, thus its influence was widespread.

A generation later, England's Charles John Hill first developed his machine in 1851 with further improvement in 1856. While he may have seen James Watt's improved diecutter at the Soho Mint, he most certainly had knowledge of the Contamin. Hill's die-engraving pantograph was patented in 1866 and at first he only wanted to do die-cutting reductions, preferring not to let the machine out of his control. It was only when William Wyon purchased Hill's machine, obtaining all rights to it that it could be sold to others. It was built and marketed by George Wailes & Company, a machinery manufacturing firm of Vauxhall.

Victor Janvier's period of developing his remarkable machine occurred in the 1890s. An accomplished medallist, he formed a partnership in 1892 with Paul Marie Duval to do custom enlarging and reducing, to cut dies, and even to manufacture medals. Undoubtedly his dissatisfaction with existing machines, notably Hill's and Contamin's, led to his experiments to improve the mechanics and to construct his own reducing lathe.

The problem with existing reducers was the speed of the revolving model and the die block. Janvier's solution was inspired. He provided a slow revolving speed of the model at the beginning when the tracer and cutting point were both in the center. At the end he needed just the opposite speed: greater speed of the model and slower rotation of the die.

He accomplished this by pointing in opposite directions with a belt connecting them. One axle drove the rotation of the model (this was slow at the beginning, increasing in speed as it reached the edge of the pattern). The other drove the rotating chuck holding the die block (it was rapid in the beginning and slower at the end). Neither of these affected the speed of the rotating cutter point (which was driven by a belt in some machines, by a separate motor in others). Janvier’s concept was simple – a mechanical mechanism to effect the change in speeds at different stages of the die engraving progress – simple but highly effective. Janvier build his machines with the quality of a Swiss watch.

Janvier's improvements created a smooth running mechanism with watch-like accuracy. He was granted a French patent in1899 and he created a second business, Ateliers Victor Janvier, to commercialize on his invention by building and selling his die-engraving pantographs to mints and manufacturers throughout the world.

Janvier's machines sold but not without some persuasion. For example, the United States Mint at Philadelphia were still using their 50-year old Hill lathe – for portraits and devices as reduction punches – with decreasing satisfaction of the engraving department.

In New York City at the turn of the century a couple of German brothers who were in the ladies handbag business sent a new employee, French-born Henri Weil, to France to see why the metal decoration of French handbags were better than any other. Weil cabled the Deitsch Brothers, the decoration was made on the best reducing machine manufactured in Paris, a Janvier.

The Deitschs wired in return: "Buy machine. Learn its operation. Bring to New York." Weil did just that, bringing the machine back with him in 1906. This was the beginning of the Janvier in America and what was to become the Medallic Art Company.

The Deitsch brothers liked the machine so well they became the exclusive agents for Janvier in America. But it took the intervention of a sculptor, Augusts Saint-Gaudens, and a U.S. president – Theodore Roosevelt – to insist the U.S. Mint buy a Janvier to replace their Hill reducer. It did so in 1906. The Philadelphia Mint had been considering obtaining a new reducing machine for several years. The delay in buying one from Keller Mechanical Equipment Co., or some other, was the indecision by Engraver Charles Barber. The President’s pressure forced their decision to obtain a Janvieer from the Deitsch Bros. in New York City.. Henri Weil, then an employee of the Deitschs, went to Philadelphia to instruct engraving department employees how to operate it.

Henri Weil and brother Felix were to later acquire the distribution rights of all Janvier's machines in the U.S. as a collateral business to their medal manufacturing (which continued until the 1960s) as part of Medallic Art Company, which they acquired from the Deitsch Brothers in 1909.

By 1921 Janvier's reputation was widespread and his reducing machines were in 22 countries around the world. The number built and shipped by country are listed in the adjacent box.

Number to Number to

National Private

Mints Firms *

France . . . . . . . - 33

United States. . . - 23

Austria. . . . . . . 2 14

Germany. . . . . . . - 13

England. . . . . . . 3 11

Spain. . . . . . . . 2 6

Italy. . . . . . . . 2 5

Belgium. . . . . . . 1 3

Netherlands. . . . . 1 3

Japan. . . . . . . . 1 3

Denmark. . . . . . . 2 1

Switzerland. . . . . - 2

Czechoslovakia . .2 -

Mexico . . . . . . . - 1