... Orr. Yes, Bernice was the first that guessed right, I'm tatting the so called "large centerpiece" that is on the cover of a Dover pubblication (1989). How large I can't wait to see, slowly emerging from the coloured thread dmc size 80...
The pattern calls for a size 40 thread and it's only written instructions.
If you like reading about the history of Anne Orr, there's a page in the site: "The ShuttleSmith Tatting" (by Karen Bovard).
Among a lot of great tatting resources, you can find there the history of the split ring technique and you discover that originated in a tatting booklet published in 1918 by Anne Orr.
UPDATE: Article at Bella Online: "The Split Ring in 1901??"