This free pattern originally published in:
Spool Cotton #109, A Bookful of New Edgings 
Nothing is daintier and more feminine than fine handmade lace edging your lingerie. Slips, panties, nighties – edge them for yourself – or edge them to make a trousseau type of gift.
Use
Clark's O.N.T. or J. & P. Coats Mercerized Crochet, sizes 50 to 80.
J. & P. Coats Tatting Cotton.
To begin, make a chain to measure slightly longer than length desired. 1st row: S c in 2nd ch from hook and in each ch across. Ch 5, turn. 2nd row: * Skip 3 s c, s c in next s c, ch 5. Repeat from * across. Ch 4, turn. 3rd row: * 3 d c in center ch of next ch-5 loop, ch 3, 3 d c in same ch, s c in center ch of next ch-5 loop. Repeat from * across. Break off.
other patterns in leaflet: