This reversible edging went with the Leeds Shawl, p.171 in 1912 Fleisher’s Knitting and Crocheting Manual. The edging starts with 15 stitches and increases 1 stitch every front-side row to 19 stitches, then decreases at the same rate to 15 stitches in the last pattern row (row 16).
Yarn overs are the very first stitches at the zigzag edge. My yarn overs on the edge aren’t very “loopy” because I’m a tight knitter. Your results might be lacy-er.
The swatch is 2.25 inches at its widest at gauge.

Skills needed: cast on, slip, knit, purl, YO, YO twice, k2tog, SK2P and bind off in knit stitch.

Gauge is not important in this pattern. Any block-able yarn/thread will work. Make a swatch to check gauge and appearance.

35 yards of Aunt Lydia’s Classic 10 thread will make 10 inches of Leeds Border at gauge.