Hard Evidence

The 1792 half disme occupies a unique, almost legendary space in the story of early American coinage. For generations, catalogers have repeated familiar anecdotes regarding the source of its bullion and its hasty production under the supervision of Chief Coiner Henry Voigt. One could be excused for thinking that after 234 years, the half dismes have taught us everything they can about the precursor to the Philadelphia Mint. However, it would appear that at least some of these tiny pieces still carry secrets that are waiting to be revealed.

An Interesting Specimen

At the recent World’s Fair of Money^® convention, I had the pleasure of speaking with a client of Kagin’s who took the time to show me a high-grade 1792 half disme from his collection. He pointed out that his specimen was struck from a rare, relatively late state of the dies, as evidenced by what researcher Pete Smith described as “a raised curved area like the top of an S” to the right of the A in HALF. 

He allowed me to examine the coin. When I louped it, I noticed that the raised area not only looked like an S, but it was also of the same size and shape as the S of DISME located directly below it. I then noticed a die lump directly above the A of HALF that appeared to be the same size and shape as the left serif and upright stroke of the A, as well as a vertical die lump between the H and A of HALF that resembled the I in DISME and remnants of what appeared to be the M of DISME next to the L of HALF (shown). All of this was surrounded by spalling (chipping, flaking, or pitting of the die’s surface), a feature Smith noted on relatively late die state half dismes.

The combination of these features suggests that the words HALF DISME were originally punched into the die around 1.5mm above their current location. For some reason, it was decided that the original location was incorrect, and the dies were reworked to correct the bungled placement of the denomination. 

What the Letters Revealed

The alignment and geometry of these ghost letters provide us with critical clues regarding the working practices at the early mint. A photo overlay of the words HALF DISME as they appear on the fully realized coin and the vestiges of the letters A, I, S, and M suggests a gang punch was used rather than individual letter punches to sink the denomination into the die. The use of a gang punch at this stage of the mint’s development suggests a level of sophistication on the part of the die engraver. 

The method by which these misplaced letters were removed from the die is equally compelling. Had the die-sinker replaced the die or ground it down, there would be no evidence of the original letters. Instead, the surfaces surrounding the phantom letters exhibit spalling with an eroded, slightly pitted texture that is inconsistent with mechanical polishing.

In fact, the texture on relatively late die state half dismes is characteristic of chemical etching, which is most likely the result of the die-sinker’s use of acid to dissolve the die face around the misplaced letters. Once the unwanted words were removed from the die, it was resurfaced, re-engraved, and placed into service. Initially, the die face would have been smooth; however, exposure to acid leads to hydrogen embrittlement in metal. After being used for a while, the surfaces that were treated with acid would begin to flake and chip, resulting in the rough surface seen today on some relatively late die state examples.

Early U.S. Mint Technology

In numismatic research, the physical coin must always serve as the primary document. This evidence suggests that the artisans of 1792 balanced a shoestring budget and severe time constraints with sophisticated tooling in the form of a gang punch and efficient, albeit imperfect, chemical treatments to contend with die-sinking errors. From this perspective, the 1792 half disme represents a sophisticated intersection of metallurgy, chemistry, and experimental engraving at the dawn of federal coinage.