Pattern is from an old Italian pubblication, "Nuovo manuale elementare dei lavori delle dame secondo le più recenti variazioni della moda", 1868. It is free in Google books.
It's highly precise, unusual indeed for that period. They gave also the right measure for bare threads and picots!
The same rosette is in the "Beeton's Book of Needlework"(1870), fig.12 -"circle in tatting", and there are others patterns in common. It is interesting that the shuttle showed in the Italian version is a flat shuttle.