9-9 Flagstones is the name Ladies Art Company gave this block when they added it to their catalogue in 1928. We called it Snowball and 9-Patch. Other names are Aunt Patsy’s Pet and Federal Chain (Nancy Cabot, Chicago Tribune,1936), Aunt Patty’s Favorite (Farm Journal and Farmer’s Wife,1945), Dutch Mill and Pullman Puzzle (Lady’s Circle Patchwork Quilts#22), Grandmother Short’s Quilt (Goodspeed), Delaware’s Flagstones (Workbasket,1935), Fancy Tile (Needlecraft Supply,#60,c. 1939.
Double X is pattern in the original Ladies Art Company catalogue, so was in print from at least Carrie Hall kept the name Double X in her 1935 reference book, but it was called Wild Ducks when it was published by Needlecraft Supply c.