Wednesday, July 25, 2012

Channeling: Narrow gutters interpreted as hub retouching


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A shallow gutter outlines Lincoln’s forehead and nose in this 1942 cent. According to Neff’s theory, this channel represents retouching of a master or working hub.
Image by Mike Diamond.
A long-established resident of my box of odds-and-ends is a 1942 cent whose image appears here. Its sole peculiarity is a shallow gutter that runs alongside Lincoln’s forehead and nose.
At first I thought it was a manifestation of die fatigue, since some coins struck by worn dies do show a form of incuse die deterioration doubling. However, the coin doesn’t show any other signs of die wear. I was later told that the effect is very common on cents of this period and is somehow related to the die-making process. Beyond that, I didn’t have a clue and didn’t pursue the investigation any further.
Unbeknownst to me, the problem was taken up by Robert (“BJ”) Neff, a noted researcher of die varieties and die errors. Neff has been the driving force behind the study of trails, a hubbing-induced form of die deformation.
Neff patiently accumulated a large sample of coins with guttered design margins dating from the first half of the 20th century. Every denomination was affected to a greater or lesser degree. The location, width, clarity and frequency of the gutters all led Neff to conclude that they are caused by retouching of the master hub, the working hub or both. He calls the phenomenon “channeling” and his detailed analysis can be found on the Error-Variety Ready Reference (error-ref.com/Retouching_of_design_elements.html).
Channels can be found on coins from the early 1920s to the late 1940s. They are most easily spotted where they outline large centrally located design elements like busts. The illustrated 1937 Lincoln cent shows a narrow but sharply defined channel outlining Lincoln’s profile. The channel is narrower than the one on my 1942 cent.
Channels can also be found in the interior of the design. The 1943-D Winged Liberty Head dime pictured here shows a channel along Liberty’s face, with additional channels outlining the forward margin of her hairline, the lower margin of her wing and some individual feather vanes.
Many Washington quarter dollars from the 1940s show channeling around Washington’s queue (“ponytail”) and bow (see photo). The near-ubiquity of this channeling on the quarter dollars indicates to Neff that the retouching was done on the master hub that was used to create the master dies of this period. Other parts of Washington’s bust are less frequent targets of channeling. The front, top and back of the bust sometimes show added channeling, while at other times only the face is channeled. Neff has never observed channeling along the base of the bust.
These less frequent targets of channeling suggest to Neff that the retouching was done on assorted working hubs. A single working hub will create a number of working dies, but far fewer than can be traced to a single master hub.
While most channels show no obvious signs of mechanical action, a few do. A close-up photo of several channels outlining the rays of a 1923 Peace dollar shows the formation of a pressure ridge at the base of each channel, right next to Liberty’s hair. Other channels (not shown) appear to have been carved in twice.
The question now turns to why this retouching was done in the first place. Charles Daughtrey, author of Looking Through Lincoln Cents and creator of the website coppercoins.com, suggests that it was an attempt to extend the useful life of the hubs. While it’s likely that most retouching was performed on newly fabricated hubs, this might not be the case in all circumstances.
It’s not clear why the practice was abandoned mid-century.
Coin World’s Collectors’ Clearinghouse department does not accept coins or other items for examination without prior permission from News Editor William T. Gibbs.

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