The impressions on the plate are pressed into the plate individually, which results in images being all over the place relative to the images immediately adjacent. This was the technology of the 1850's. I suspect (but don't know) the process was done by hand. If not by hand then, apparently, the machinery used had lots of wiggle in it.
I collect early USA (1847, 1851 issues) and this is common. Extreme examples make this era interesting!
It also seems that the spacing between the two is much smaller than the area on the left. Could they be stamps from the left and right pane of a larger sheet? If they were coils they could be where the plates meet
the art of engraving steel especially : a process of multiplying facsimiles of an engraved steel plate by rolling over it when hardened, a soft steel cylinder. And then rolling the cylinder when hardened over a soft steel plate.
And then rolling the cylinder when hardened over a soft steel plate. This is where the siderographer miss judged the position, of one of the roll ins.
Quote: The siderographer had significant problems placing the transfer roll at the correct position on the plate for each entry. Specialists of the issue believe the problems resulted from the plate being too thick, reducing the spacing between the transfer roll and the plate, thereby reducing the siderographer's visibility of the layout lines or position dots.
The siderographer frequently had to reposition the transfer roll after starting an entry at a given position then realizing the entry was out of alignment. At some positions, four, or even five, total entries were made.
Sorry to jump in, I can't rely on somebody to ask my silly questions, -what plate are the penny blacks? ( seems that the A's shift, would be confusing without it in sheet to plate?) -what are the measurements of the one penny blue? (seems it might be about quarter mm bigger?) seems like this may happen in corner stamps, I'd guess micro impressions cause by the paper being pulled into the die But just a guess, Probably just more nonsense but figured Throw it out
Not such a silly question. Both the top block and bottom row appear to have been printed from plate 1, after hardening: i.e., 1B. Good to check that the two parts indeed came from the same plate at least. Now, they should also come from the exact same sheet (not so convinced they do, but difficult to be sure).
The letters do not shift. They were inserted by hand. The different shapes and positions were studied by Charles Nissen and he identified the individual stamps from the eleven plates. Plate 1 exists in two states, known as 1A and 1B. This study helps stamp collectors to plate their examples of the Penny Black.
Similar studies have been conducted for the many Penny Reds.
Pulled into the press? When do you think these were printed?
I should have said as the press came down maybe? It's like a vibration, pulling the image ( perhaps the deepest point in the die off in size) And I should have said edges not just corners But the paper has to flex somewhere,no?
Search for paper shrinkage. That could cause some variation in size, but between sheets or even printings.
If the press came down (as it did not) why should there have been any difference at an edge? What edge? Who says these stamps were not from the centre of the top right quarter or the top right of the bottom left quarter of the sheet?
But what is your point with the size? Where do you see a size difference? The stamps are at an angle and the clichés appear to have been displaced. They are not lined up perfectly making a size difference easily observable.