I recently scanned a number of Artrio-Angelus rolls, and in doing
so I was struck all over again by their similarity to Duo-Art rolls.
After some investigation, I have come to the conclusion that these
two types of rolls were manufactured using the same perforators.

There are good reasons for believing this.  Dave Krall informs me
that Artrio-Angelus rolls were made at Aeolian's roll-perforating
facility across the street from Wilcox and White (the makers of the
Artrio-Angelus), at least up to the bankruptcy of Wilcox and White
and the subsequent takeover by Conway in 1922.

In addition, Artrio-Angelus rolls and Duo-Art rolls are similar in
appearance; they both have the black metal spool ends characteristic
of Duo-Art rolls of the period.  They often have the same type of
tabs, including in many cases tabs with the Aeolian logo and the name
"Aeolian" across the bottom, always obliterated with a felt-tipped
marker on Artrio-Angelus rolls.

There is further evidence of common manufacture.  The perforations in
the rolls seem to be identical.  The diameter of the holes other than
the snakebites is 1.70 to 1.80 mm in both types of rolls.  It is well
known that the leftmost four port positions of Artrio-Angelus rolls
are offset from their nominal 9-per-inch centers toward the left edge
of the roll by about 0.8 mm, and we find that Duo-Art rolls from the
same era have corresponding offsets.

To my mind, the conclusion that the two types of rolls were made on
the same perforating machinery is inescapable, but I am aware that
I may have overlooked something.  I want to get to the bottom of this,
and to that end this note is a plea for help.  If you have any reason
to believe that Artrio-Angelus rolls and Duo-Art rolls prior to 1922
were _not_ made on the same machinery, please contact me.  I greatly
appreciate your help!

Wayne Stahnke
Reno, Nevada