Crochet cotton size 20. Steel crochet hook US size 9 or size for gauge.

First three rounds = 2” in diameter.

Advanced. Two mirror image sections join-as-you-go with a one-round border.

Pattern 7, page 13 in Decorative Crochet.
Pattern 11, Gemeaux, in 1000 Mailles.

This pattern also published under the name Flower Lake in Elizabeth Hiddleson Volume 17, Crochet Originals. There size 30 thread and 1.00 mm hook are used.