This free pattern originally published in the Woolco Knitting & Crocheting Manual, in 1916.

MATERIAL-2 skeins white and 2 of color Woolco Germantown Zephyr. No. 3 ½ Woolco hook.
With color, chain 4, join with a slip stitch.
1ST ROW-12 single crochet in ring. Join every row with a slip stitch. Do not break off yarn.
2D ROW-With white, *2 single crochet in 1st stitch, taking both loops, 1 single crochet in next*. Repeat around, join with slip stitch.
3D ROW-With color, *2 single crochet in 1st stitch, 1 in each next 2 stitches*. Repeat.
Repeat 2d and 3d rows, always alternating colors and increasing in corners each row.
6TH ROW-Make 4 single crochet in each corner. Repeat until there are 10 rows in all.
11TH ROW-Work 16 stitches, turn, chain 1. Repeat this row until there are 29 stripes, making each stripe 2 rows. Join to other side of square with a slip stitch. Fasten off.
TOP-With white, make 1 row of *1 double crochet, 1 chain* in every other row. Join with slip stitch.
2D ROW-*1 single crochet, 3 chain, skip 1 space*. Join.
3D ROW-With color, *8 double crochet in each chain 3,* Join picot with white, make 1 single crochet, 3 chain, 1 single crochet in each stitch.
CORD-With color make a chain ¾ yard long, work back with a slip stitch.
BALLS-Both colors.
Other great socks and slipper patterns from Woolco Knitting & Crocheting Manual.
Slipper I
Slipper II
Slipper III