Franklin I.d. (#522) But Odd Perforation?

Spectacular photos, Russ! Are these from a single book/publication or compiled from multiple sources? I'd like to know the name(s) of the book(s) if possible!

ME TOO!

Very helpful Sir Russ! I learn so much stuff from the "forum sages" such as (in no particular order) Russ, wt1, Revenuecollector, Revstampman, stampvirgin, Rileysan, and all the others that I can't recall this minute that make this site what it is! Supurb!

They are from multiple sources mostly from Library of Congress photographic archives and Smithsonian photographic archives. These two institutions have amazing photo archives.

I have measured many of the 1922-1926 series issues that measure weirdly. It seems to me to be most common long side of perf. 11s, but I have seen it on the short side. And also on the perf 10.5s. I call this "perf stretching". Since it is so common and there aren't any listings for compound perfs for these issues, I think the measurements might be the result of expansion caused by some soaking/drying practices. Design measurements could prove/disprove this.

Both of the rotary presses shown are for the wet printing process which uses about 30% moisture. The long portion of the press (that looks kind of like a table) is the drying chamber. The shrinkage can adversely affect centering but not the perf spacing since the stamps are dry at the perf operation. There was inherant variability in the system simply as the design perforated both directions on a moving printed web.

The rotary press did have a moistening station in it so that the moisture content and the drying was much more controlled resulting in a more consistent shrinkage.

Sorry, but the area of the rotary press marked in red was the paper wetting station and not the two way perforating station since all stamps were perforated only after the paper was gummed at the gumming station and the gum was dried first. If the stamps were perforated before they were gummed, there would be gum getting into and clogging the perforation holes, but there isn't. The Stickney rotary press perforating was done offline (off the printing press) on the type of perforator that you showed which is a wheel and bar perforator (2 way perforator) for handling rotary press rolls and perforating them both vertically and horizontally on one machine in one continuous operation.