Preface.
Missing circle notes always end with numbers ranging from 500 through 999. This would indicate that they were printed in a 10x4 format or a 9x4 format. In fact they were printed in both formats, 10x4 through FEE(2001) and 9x4 starting with FEE(2002). (See article by Don Roebuck in March 2004 CPMS Newsletter - CBN Journey $10 Sheet Formats-) With either format the potential for missing circle notes is 25%, 10 out of 40, or 9 out of 36.
Observations.
From observations based on viewing about five thousand circulated notes per week over the past three years or so, the frequency of missing circle notes in circulation is well below the theoretical potential. It is recognized that the sample is small compared to the total issued and the sampling area is minute compared to our country, but if we believe in random distribution, the numbers should be close.
In their hayday, when a large percentage of circulated notes fell within the prefix range of FEB through FEE(2001), the frequency of missing circle notes, within each prefix that produced them, was 11%.
With the change of format from 40/on to 36/on, something else happened. The frequency of missing circle notes, although still at a potential 25%, dropped drastically to less than 5% for FEE(2002) and less than 1% for subsequent prefixes. The reason for this change could be as simple as greater attention to the cutting registration, or perhaps a more subtle effect of the format change.
It is generally accepted that missing circle notes are produced by the before mentioned cutting registration. There is however a secondary cause related to the registration in the printing processes. Specifically the registration of the orange printing containing the missing circle relative to the intaglio printing. This difference became apparent in a brick of FEG notes with 4 FEH insert notes in each half brick. The FEG position numbers of the lower half brick were those of missing circle notes. The cutting registration was such that none of the FEG notes showed the missing circle. However, the four FEH Inserts in the lower half brick were missing circle notes. The only difference was the orange printing relative to the intaglio, it was further to the right on the FEH insert notes than it was on the FEG notes.
Missing circle notes have been observed for FEB, FEC, FEC Inserts, FED, FED Inserts, FEE(2001), FEE(2002), FEF, FEG, FEH, FEH Inserts, FEJ, FEK, FEL, FEM, FEM Inserts and FEN. (I have not seen or heard of any FEN Inserts with missing circles.) Thus far the series appears to comprise 17 notes.
Of the know missing circle notes, the FEH Insert is the only one that I have not found in circulation.
Conclusion.
The purpose of this writing is two fold. Firstly, to share my observations with the members of this Forum. Secondly, to elicit discussion so we can all be more enlightened about this interesting variety.
Thank you for your attention and hopefully your contributions.
JWS
