Shoebox Comptometers - Serial Numbers

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The very first wooden-cased Comptometers did not carry serial numbers and it is uncertain exactly how many were produced. The very earliest known "serialized" machine carried #135 (not #136 as sometimes reported). Based on Felt's later habit of starting new models with a mod-5000 serial number, it is assumed that he would have started serializing with #100 to allow for the prior unserialized machines altho this is by no means a certainty.

Starting with the C-model, serial numbers were engraved next to the 1-key of the leftmost column of keys. The wooden-cased and A-models had the number on the front while the B-model seemed to try to hide the number between two of the carry-inhibit tabs just beneath the 4th and 5th columns. To the best of my knowledge, all Compts also had a matching number stamped into the left side frame of the mechanism.

Clearly, if a model started with a mod-5000 number, its safe to assume that the first machine of that model carried that number. What can not be assumed is what number was on the very last machine of that model!

Note that it cannot be assumed that a new model would carry the next logical "mod" number since, it appears, there was something of a "numbering war" taking place with competitors; sort of a "King of the Hill" mentality. That this occurred with the wooden-cased models is evident since the last known such machine is under 7000 and the next (A) model started with 15,000, skipping the obvious 10,000 choice.

The serial ranges shown on The Models page and elsewhere indicate the starting mod number and sometimes the earliest and/or highest discovered numbers.

Following is a list of all shoebox models and their known serial number ranges together with a conservative count of the number produced...

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 Model   Start#  First#  Last#   Count  Comments
-------- ------  ------  ------  -----  -------------------------
Wooden      100     135    6121   6122  earliest few machines unserialized
  A       15000   15242   16903   1904
  B       25000   26790   27315   2316
  C-      35000   36371   36604   1605
  C+      40000   43503   48475   8476
  D       49000   49000   49154    155  Src: Amer Digest
  E       50000   54005   60077      ?  serial numbering unreliable
  F*     100000  100249  141722  42455
  H      200000  200109  248508  48509  Last# is a British Greenee (£s¢)
  J**    250000  249633  345721  95722  #249633 defies the "mod" hypothesis
Documented production count:    207262  (shoebox models only)
*starting with the "F", 90% of all shoebox models sold will be Fs, Hs and Js
**includes Supertotalizer