US Stamps

The Bowlsby split-grill coupon essays, explained

Jan 12, 2017, 12 PM

By James E. Lee

By 1865, the National Bank Note Company was determined to acquire the rights to any and all prevention and reuse patents that might pose a threat to their contract to produce United States postage stamps.

George Bowlsby’s coupon essay patent was one of these acquisitions. National Bank Note went so far as to engrave a die and enter a plate of 50 subjects. Production commenced of red and blue varieties, both perforated and imperforate.

An example of the Bowlsby die essay in blue (Scott 63-E13a) is shown in the first illustration.

Connect with Linn’s Stamp News: 

    Sign up for our newsletter
    Like us on Facebook
    Follow us on Twitter

One of the red imperforate sheets (Scott 63-E13d) was removed from the files and subjected to being grilled in either 1867 or early 1868. This variety became Scott 63-E13e. This listing also includes a sub-variety referred to as a “split grill,” which is the subject of this column.

Lot No. 1139 in the September 1999 Robert A. Siegel sale of the Falk Finkelburg collection was described as: “1c Red, Bowlsby Patent Coupon, Plate Essay on White Paper, 13 x 16mm Grill (63-E13e). Block of six, original gum …”

This is the only large multiple of this essay that I know of that still exists. This block is pictured front and back nearby. It is a block of three over three from the lower left corner of the sheet, as indicated by the large selvage at the left and bottom.

To make the grills easier to see, I carefully applied graphite to the back of the block. 

I acquired this lot with the hope that it would answer the age-old question about the position of the split grill. I have long thought that only one sheet was produced with the split grill.

Over the past 40 years, I have recorded no more than three examples with a true split grill. The Finkelburg block provided the answer.  

I believe that the split-grill examples come from a single 50-subject sheet. If my theory, which follows, holds up, there can be no more than a total of 10 split-grill examples, which comprise the entire second horizontal row of the sheet. The drawing shown nearby provides a visual illustration of my theory.

The original Bowlsby coupon essay plate was laid out with 10 subjects across and five rows down for a total of 50 subjects. Each entry is 48 millimeters tall.

This can be compared to a vertical pair of the 1¢ Benjamin Franklin stamp (Scott 63), which is 52½mm tall including the spacing between the stamps. This makes the vertical layout height of the essay plate about 18mm less than a typical 1¢ 1861 stamp plate.

The experimental “C” grill roller contained the same number of grills as a stamp plate, 100. The grills were laid out on a roller 10 across and 10 down just like the stamp plate. 

This was done so each stamp would receive a grill impression when the sheet was grilled. Therefore, each of the Bowlsby plate essays should have received two full grill impressions.

The answer to the mystery lies with the block of six. When you superimpose a layout of the grill images over a layout of the coupon essay images, you find out that the grill images do not line up exactly, with two full grill impressions for every coupon essay.

The coupon essay is 48mm tall with 2mm spacing between horizontal rows. The “C” grill is 15mm tall with 11mm or 12mm of spacing between horizontal rows. Therefore, the grills seem to float in terms of their position on each of the horizontal rows of coupon essays.

Working from bottom to the top, each essay of the bottom row has two full grill impressions. The fourth row has one full impression and 13 of the 15mm of the second grill. 

Therefore, examples from row three should show about 2mm of grill at the bottom, a full grill in about the middle and about 7-8mm of grill at the top.

Row two would exhibit what is called the split “C” grill with 7mm to 8mm of the grill at the bottom, one full grill in the middle, and 7mm to 8mm of grill at the top.

The top row would contain half a grill at the bottom and a full impression above it. Thus the true Bowlsby with the split “C” grill can only come from the second horizontal row of 10.

If you have an example of the Bowlsby split grill, I would like to see it. Please email a scan of both the front and back to me at the address below.

James E. Lee has been a full-time professional philatelist for more than 25 years, specializing in United States essays and proofs, postal history and fancy cancels. He may be reached via email at: or through his website: