All stamps displayed in this thread so far have a parallel watermark!!!
The first orthogonal watermarks are assumed to have come from England and have a SMALLER sun!
Look at what Hickethier shows us:
The "horizontal" watermark - whatever horizontal means in this context!!! - was used for all values and has the direction of paper (eje de enrollamiento) horizontally. The diameter of the sun is 8mm. This is exactly what we find at the orthogonal watermarks!
The only other stamps with a horizontal direction of paper have a much larger sun (4c, 5c with AЯ or 2c, 5c with RA)....
.... and as I am showing above a diameter of 10mm
to be continued ...