In any field of inquiry, unique or ambiguous examples often resist
analysis. But confusion often lifts with the acquisition of a larger sample.
Case in point is a 1994 Lincoln cent that was discovered by Andrew
Heebner and discussed in the May 24, 2010, “Collectors’ Clearinghouse”
column. It features an extra set of die-struck letters (from in god we
trust) on the northern arc of the design rim. At the time, I toyed
with several explanations but failed to commit to any of them.
Comparison with a 2004 Lincoln cent with extra lettering on the
reverse rim (“Collectors’ Clearinghouse,” Feb. 22, 2010) failed to
clarify the situation.
Additional cents offer proof
I have since acquired two more 1994 Lincoln cents with obverse rim
lettering, and these prove to my satisfaction that the extra letters
represent a peculiar form of machine doubling. Machine doubling arises
immediately after a coin is struck, when a die bounces, shifts
position and makes light contact with the coin’s surface.
One of the cents was acquired from Robert Risi and the other from
Rick Rodriguez. Both cents are shown here along with the 1994 Lincoln
cent that was profiled in May 2010. Two die pairs were involved, with
the Risi and Rodriguez cents traceable to the same die pair. It’s not
clear whether two coinage presses were involved, since both die pairs
could have been installed in the same malfunctioning press on
The shared characteristics of these three coins support a machine
doubling scenario from several standpoints:
(1) A true double strike of such peculiar appearance would be a
one-off event. Three virtually identical examples suggest a repetitive
(2) The obverse die was slightly misaligned toward the south when
the normal strike was delivered. This implies that the obverse die
bounced up after impact, shifted back north to a centered position,
and landed lightly on the rim.
Oscillating die movements are well-documented among a variety of
different striking errors. For example, conventional machine doubling
can be oriented in opposite directions on the same face. Also, some
coins struck by a misaligned hammer die will show machine doubling in
the opposite direction.
(3) The reverse face shows moderate to strong machine doubling of
the conventional sort, with marginal shelving on the affected design
elements. The machine doubling is strongest around one cent, the area
opposite the rim lettering in vertical space.
Conventional machine doubling will sometimes appear on both faces.
A fourth line of evidence confirming the presence of die
instability and the secondary nature of the rim lettering was provided
by the Rodriguez coin. Some of the letters were damaged by die contact
after they were applied to the rim. It appears that after landing on
the rim, the hammer die bounced up once more, rotated slightly,
shifted southward again and sank down toward the field. During this
last movement, the field portion of the hammer die caught the internal
margin of some of the letters and dragged the metal downward along the
internal margin of the design rim.
It’s clear that the smearing of the letters is not the result of
the impact that delivered the normal design. The relocated metal is
rather loosely adherent to the internal margin of the design rim and,
in certain areas, does not even reach the surface of the field.
Answer not surprising
While machine doubling was not the hypothesis I originally favored
for Heebner’s coin, I’m not particularly surprised it turned out to be
the answer. After all, in the Dec. 6, 2010, “Collectors’
Clearinghouse,” I was able to show that the rim-restricted design
duplication found on the reverse face of Presidential dollars is a
form of machine doubling. Here it wasn’t a larger sample that provided
the answer. Instead, a particularly informative Proof dollar that
combined accessory rim elements with standard machine doubling was the key.
Henceforth, unless compelling evidence indicates otherwise, I will
assume that all cases of rim-restricted design duplication confined to
one face are examples of machine doubling.
How to contact Collectors’ Clearinghouse
Coin World’s Collectors’ Clearinghouse department does
not accept coins or other items for examination without prior
permission from News Editor William T. Gibbs. Materials sent to
Clearinghouse without prior permission will be returned unexamined.
Please address all Clearinghouse inquiries to firstname.lastname@example.org or to
(800) 673-8311, Ext. 172.