This stitch forms a lattice with the chains peeking through. It can have a lovely effect when worked with variegated yarn. It biases strongly to the right. (It ought to be okay in the round, though.)
Original instructions from the book:
A suitable stitch for couvrepieds when made in thick fleecy wool and with a large No. 8 bone hook, but which does not look well worked with fine cotton. Make a foundation chain of an even number of stitches, work a row of Tricot, and work back. Second row--Work the first stitch plain, and then put wool round the hook, bring it out at front, push the hook through the next two long loops, still keeping the wool before the work, put wool round hook, as shown in Fig. 221, and draw it through the two loops. Put wool again round hook, thus making a stitch for the one lost in the work, and continue to end of row; work last stitch plain. Draw the wool back through the edge stitch, and then through two stitches, as in Tricot. The second row is repeated throughout.
Make a chain with an even number of stitches, and work a foundation row of TSS and back.
Bring the yarn to the front of the hook, and then over.
(For the knitters among you, this is structurally the same as *yo, p2tog*, except for the chaining back part, though the maneuvers to get there are different.)