An in-depth analysis of the 1888 MPD-001/RPD-001

>>An in-depth analysis of the 1888 MPD-001/RPD-001
An in-depth analysis of the 1888 MPD-001/RPD-001 2016-03-06T14:18:06+00:00

Home Forums Flying Eagle and Indian Head Cents Forum An in-depth analysis of the 1888 MPD-001/RPD-001

Viewing 1 post (of 1 total)
  • Author
  • DVCollectorDVCollector
    Post count: 103

    An Analysis of the 1888 RPD-001/MPD-001
    It’s been argued that for this variety, also known as the Snow-2, that a single 1888/888 RPD explains the position and characteristics of the markers in the date, including an external mark outside the last 8 (arrow). The top image, fig. A, shows this proposed RPD position, and the second, fig. B, proposes why the S-2 cannot be an 1888/7—the original date would be too low, into the denticles. However, it’s also rather clear that neither diagram provides enough detail to either confirm or refute these claims.

    fig. A
    S-2 date
    fig. B
    'debunked' 1888/7
    Photo credit: Heritage Auctions

    Position of the proposed 1888/888 analyzed with better data.
    Since the prior images lack clarity and much useful data, let’s instead use some high-quality scanning electron microscope (SEM) images generously provided by Chris Pilliod. We’ll then add carefully traced date overlays for a more detailed analysis of the proposed 1888/888:

    fig. C
    SEM image of markers
    All SEM images used with permission, © Chris Pilliod

    Figure C above is an SEM image of the date area of this variety. Figure D below shows an RPD overlay positioned as in fig. A, as a way to explain both the RPDs and the mark extending from the last 8—light arrow.

    fig. D
    Proposed 1888/888 overlay
    All SEM images used with permission, © Chris Pilliod

    With better variety data and more accurate overlays, it’s now possible to scrutinize this proposed RPD carefully and decide if the position shown in figure D is a good explanation for all the details present.

    Does the proposed RPD match the visual evidence?
    Figure E, below, shows a close-up of the second 8, pointing out the arc of the RPD inside the top loop (two arrows), and the proposed position of the RPD from fig. D to explain these marks (b.). Notice how the proposed RPD position is aligned over the thicker mark, but it misses the crisply defined, tighter arc to the left (dark arrow)?

    fig. E
    closeup of proposed 8/8
    All SEM images used with permission, © Chris Pilliod

    Observe the markers in a. against the proposed 8/8. Note how the dark arrow points to a tighter, more crisply-defined curve, while the light arrow points to a flatter curve that raises more metal on the right inner loop of the 8? The proposed position of the RPD from figure D, appears to be more or less aligned to the right curve, although it misses the left-hand, sharper curve completely.

    Details matter, so let’s now compare these two proposed RPD positions using much greater resolution. Part a. is the position argued in figure E, part b. (above). Although the right curve loosely matches the overlay, it doesn’t remotely follow the sharply defined curve on the left (dark arrow). Detail b. is my proposed 8/8 position, which fits very well to the sharpest details. But if true, why doesn’t this loop position also correspond to the wider, blunter mark on the right? This will be discussed in the following paragraphs.

    fig. F
    closeup of two proposed 8/8 positions
    All SEM images used with permission, © Chris Pilliod

    What might explain the different curve profiles inside the 8 loops?

    To consider what is seen inside the 8, we need to think about the shape of the punch. As we don’t have these punches to study directly, we will infer their shape from the digits in this high-quality image, below in fig. G.

    fig. G
    Comparison of curve profiles
    All SEM images used with permission, © Chris Pilliod

    I would submit that in side a., the difference in sharpness and contour between the fine, curved mark on the left and the thicker, flatter mark on the right is best explained by different positions on the punch. In detail b., I have highlighted the tighter, inner curves on the “8” punch in red, and the flatter contours in blue. It’s easy to see why the narrower portions of the date punch must use a steeper profile to cut an impression into the die: they would drop out otherwise. The wider areas of the punch define themselves more easily by size and shape.

    Consequently, above we see a sharply-defined arc on the left corresponding to the red curve in figure G above. And where the loop curve flattens, the punch profile is less pronounced. Here the punch is wider; it will exert less pressure when impressed into the die. Since the punch profile is more gradual there, it will leave a less curved and broader impression. When this underlying digit is subsequently polished away, what remains of the flatter punch section will be a blunter area of raised metal, which predicts the profile of the right-hand curve (lighter arrow).

    Which 1888/888 position more closely matches the observed details?
    Now let’s zoom out and compare the two different proposed RPD positions—figure H below. The first version (a.) argues that the 1888/1888 explains the RPD, including the mark outside the last 8 (arrow). My proposed date position is b., which I would argue better explains observed details inside the loops, as discussed in detail previously.

    fig. H
    comparison of two RPD positions
    All SEM images used with permission, © Chris Pilliod

    Notice that in detail a. above, the overlay doesn’t match those crisp arcs seen inside the left inner loops—on any digit? This is shown very clearly in fig. F, detail a. How would these sharper marks be impressed into the die if not by the loop inside the punch? On the other hand, the overlay in detail b. matches the upper loops very closely on the left, with the broader marks explained by the wider contour of the punch, as discussed for fig. G. My proposed 1888/888 position does not seek to explain everything seen, only specific details with more accuracy.

    What is the significance of the marks in the last digit?

    Now let’s take a closer look at the last digit, as it shows details that help us analyze the various claims. Figure I below shows a., the mark that is claimed to be caused by an 8/8. However, notice how this mark is thick at the boundary of the 8, then branches into two directions (arrows)–what is happening here? I consider that an important, supporting detail. Here, b. is the continuation of the 1888/888 RPD into the last digit, which follows my overlay as shown in figure G, detail b. Finally, Detail c. has been called a die crack or die damage, but I believe there may be another explanation.

    fig. I
    closeup of details in last 8
    All SEM images used with permission, © Chris Pilliod

    Can a single 8/8 explain everything in the last digit?
    Below, figure J shows the proposed 8/8 from figure D, apparently positioned to explain the external mark (dark arrow). While this position gets reasonably close to explaining the 8/8 at c., notice how this position doesn’t really fit the RPD markers at b., if at all? And yet this 8/8 position is proposed to explain a., b., and c.

    Let’s now look closely at mark a. below. While the proposed 8/8 position roughly coincides with the mark, it does not explain the branching, seen at the arrows. It’s been said elsewhere that RPDs will show crisply defined digit margins. If that is true, it is not very apparent here. Overall, I don’t find this RPD position a very compelling explanation, since the arcs seen don’t really predict an 8/8. In fact, it may be better explained by other digits, as I will show in the following paragraphs.

    fig. J
    proposed 8/8 to explain the outer mark
    All SEM images used with permission, © Chris Pilliod

    Now, let’s compare this last digit to a similar 8/8

    fig. K
    Comparison of 1899 S-2 to 1888 S-2
    Photo on left © Kurt Story, right all SEM images used with permission, © Chris Pilliod

    At a quick glance, the exterior curve of the 8/8 on left from the 1899 S-2 is roughly analogous to the mark on the right from the 1888 S-2. Yet, notice how the 8/8 is a well-defined, tapered curve coming to a point, while on right the mark is more irregular? That might also suggest a differently shaped punch created these two marks.

    Do any other digits better explain the mark outside the last 8?
    While an 1888/7 was previously “debunked” by positioning the prior 1887 far south into the denticles (figure B), I consider this a bit of a “straw man”, since it obviously did not happen. So let’s consider a more plausible position for 1887 on this die:

    fig. L
    Overlay of proposed 1888/7 position
    All SEM images used with permission, © Chris Pilliod

    Considering all the visible evidence, I would suggest this variety is more complex than a single RPD would suggest. Yes, there’s clearly an MPD and an 1888/888 RPD. But, I would argue that some details on the last 8 might be explained by an 8/7. But before we even consider an 8/7, let’s look at the last digit in more detail, and discuss how a 7 might better explain these marks, in figure M below.

    Compelling details on the last digit may point to an 8/7.

    fig. M
    Closeup of proposed 8/7
    All SEM images used with permission, © Chris Pilliod

    What I find most striking by this diagram is how the 7 overlay matches the details in a. compared to an 8/8. There is a visible “s-curve” which predicts the position of the hook on the 7 very accurately. Additionally, the “crack” positioned at c. (fig. I) may plausibly be explained as remnants of the 7 punch, where more pressure was exerted into the die, leaving a deeper remnant. Taken separately, these details don’t amount to very much. But together, in conjunction with the overlay, it makes for a plausible argument for an 8/7. But, rather than force a single interpretation with an overlay, let’s view it as an animation, using an enhanced detail of the last 8. Perhaps that will help us see if these details suggest an 8 or possibly traces of a 7 punch?

    fig. N
    8/7 animation
    All SEM images used with permission, © Chris Pilliod

    Looking back to figure J, detail c., it has been suggested this can’t be a remnant of an underdate, because it “has irregular, jagged margins, not smooth margins typical of an underdate”. But this argument is simply not supported by facts. From studying overdates in details, these prior digits often take on irregular marks. The discussion below will discuss possible reasons in more detail.

    A proposed mechanism for details surviving on underdates
    There are many documented cases where remnants of underlying digits take on irregular shapes. To possibly explain why this occurs, I have made a diagram (fig. O), proposing the mechanism to explain marks found inside and adjacent to RPDs and overdates. Note: details are not shown to scale.

    Detail a. The diagram begins with the original die and date impression. Note the slight irregularities in the trough of the digit punch. These are common, and caused by inconsistencies in the punch surface, pressure difference, or possibly even dirt. This is inferred because the tops of digits also show irregularities.

    In b., the die is being prepared for a new date with the prior date being polished away. From studying overdates, I see evidence that most underdates are at least polished away partially before the final digits are impressed. That is what detail b. depicts: the die surface (ie fields) have been reduced enough to remove most of the prior digit. While the digit outline may be removed, the deepest parts, which may take on irregular shapes, might easily remain. And this may explain what is seen above in the last 8, detail c.

    Below, detail c. shows a new punch being impressed into the die. For argument’s sake, let’s say it’s an 8 digit, here showing a cross-section of the top loop. When the punch is impressed into the die, some of the top of the punch will impart higher pressure than the interior of the loop. This will have the effect of flattening out any prior details left on the die directly under the punch, while some details inside the loops remain. I think this is a good explanation why repunching is seldom observed on the tops of the final digits.

    Now in d., consider what happens in the lower relief areas of the punch. For instance, inside the loop of the 8, there will be less pressure to obliterate prior die details. Also, due plastic deformation and a shallower inner loop, I would suggest the prior mark (in yellow) will be pushed deeper into the die. Consider how the blue shaded areas, along the inside margins of the loop, would impart varying degrees of pressure to prior details on the die. I think the result will be that details will be deformed and pushed further into the die—past where final polishing (dashed line) can remove. This may also explain why underlying digits are also visible on the margins of the final digit—they were pushed slightly further into the die and kept from being totally erased by the final polish.

    Finally, in detail e., after the final digit has been impressed, the fields have been polished to clean up the area. But, notice that remnants of the prior digit remain inside the loop, which were pushed beneath the fields? I consider this a plausible reason why many underlying digit traces are seen only inside the digits on Indian Head cents and other coin series.

    fig. O
    Diagram of die progression
    Diagram © Kurt Story

    How does a possible 1888/7 overdate match other varieties?

    Probably the most classic example of an IHC RPD exhibiting rough remnants of an underlying date is the 1894/1894, possibly due to varying pressure exerted by the digit punches on the die, subsequent polishing of the die, as well as die wear. For this spectacular variety, does it really look like the “smooth margins typical of an underdate”? By creating a tight overlay of this date, we can see quite clearly that much of the date has dropped out (arrows), which I would suggest is due to factors discussed above.

    fig. P
    Detail of 1894/1894
    Photo credit: Heritage Auctions

    fig. Q
    1894/1894 overlay
    Photo credit: Heritage Auctions

    The argument has also been made that markers on a genuine 1888/7 should show more evidence on the last digit and repunching elsewhere on other digits. However, if one studies the undisputed 1888/7 S-1, this overdate is visible only on the last digit, with very limited detail of the prior 7 remaining (arrows). It’s been argued that any other 1888/7 overdates should look very similar to the S-1. But, there could be many variables at work here, such as the pressure of the first date impression, subsequent polishing, and both pressure and position of the final date.

    fig. R
    1888/7 S-1 OVD main markers
    Photo credit: Heritage Auctions

    This analysis suggests the proposed 1888/888 position does not explain the observed details very well. In fact, I suspect the RPD position argued in figured D was proposed to explain that external mark to the last 8, other considerations appear secondary. Moreover, the “debunking” of an 1888/7 has simply fallen through under more careful analysis. Could this variety be an 1888/888 on an earlier 1887 die? Yes, I think that may be plausible, given the remaining details under the last 8, and the corresponding 1887 position on the original die. Finally, there’s no reason I can think of that a single die could not be an MPD, RPD, as well as an overdate. In fact, there are many IHC varieties which show similar amounts of die reworking.

    But, if we are to believe the S-2 is only an MPD and 1888/888 RPD, it’s quite frankly, a relatively minor variety. If there’s nothing very dramatic to this coin, why is it the highest price variety for 1888, second only to the 1888/7 S-1? The market price indicates this variety is in high demand, so perhaps many collectors have not ruled out another 1888/7 either?

    Kurt Story

Viewing 1 post (of 1 total)

You must be logged in to reply to this topic.