British diamond markings on covers from the United States update

U.S. Stamp Notes by John M. Hotchner

In Linn’s of Oct. 9, 2023, I looked at covers coming into the United Kingdom that received a curious diamond marking in either black or red as can be seen in Figure 1.

In that column, my friend and philatelic colleague Michael Dixon explained these markings as follows:

“Once a year, the General Post Office (now Royal Mail) conducted a census — a numerical count of mail handled. This is purely a Post Office internal exercise (which showed how workload had increased or decreased). Usually they did this one week in August or September.

“To avoid a mail item being counted twice, the items counted initially are passed through cancelling machines where the date-stamp has been replaced with an open diamond in black or shades of grey. As the postal workers ran out of fingers, thumbs and toes, every one hundredth item counted was marked with a red diamond to make the tally easier for the workers.”

After that column was published, Linn’s reader and stamp dealer Ian Billings wrote to say that the system began in the 1920s, and that for the most part, the month selected was October, not August or September as Dixon thought.

That said, I have about 10 covers with these markings, and all but a couple of them are canceled in October. The two examples shown in Figure 1 were canceled Nov. 6, 1947, and Sept 26, 1952.

Billings also quoted a paragraph from a publication of the British Postmark Society that had additional information:

“Each year to about 1985 the Post Office carried out a detailed ‘census’ of mail, normally in October, and passed mail through a machine at the office of receipt to obtain these statistics. Such items were normally stamped with a ‘census diamond’ to denote that they had been counted. In fact items could be similarly stamped at the office of posting (or an intermediate office), thus it is not unknown for a letter to receive two diamonds.”

An example of the latter is shown in Figure 2. Here, I believe the first office in the United Kingdom where the external letter was received counted the letter, and then it was counted again at the delivery post office.

The system was not limited to mail from the United States. When this method was in operation, any mail coming into the United Kingdom could receive the diamond marking.

Most of my examples are from the United States, but I have one on a letter that originated in Morocco.

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