Knit off the stitches of the first needle after the seam; then on to two spare needles, cast on, 8 more stitches than you had on one needle after dividing the stitches; put the stitches of the third and fourth needles together and knit the first round plain.
2nd round—knit together the 1st and 2nd, and the 9th and 10th of the first auxiliary needle; and the 10th and 9th and 2nd and 1st of the second.
3rd round—plain.
4th round—knit together the 1st and 2nd and the 7th and 8th of the first needle.
5th round—plain.
6th round—knit together the 1st and 2nd and the 5th and 6th of the first auxiliary needle; and the 6th and 7th and the last but one and the last, of the second.
7th, 10th, 11th, 13th, 14th, 16th, 17th, 19th, 20th rounds all plain.
8th round—knit together the 1st and 2nd, and the 3rd and 4th of the first auxiliary needle, and the 4th and 3rd, and the last stitch but one and the last, of the second.
9th round—After the two last intakes, purl together the 4th and 3rd stitches before the end of the 1st and 3rd needle, and the 3rd and 4th at the beginning of the 2nd and 4th needles.
12th, 15th, and 18th rounds—Decrease, the same as in the 9th round.