This section is from "Every Woman's Encyclopaedia". Also available from Amazon: Every Woman's Encyclopaedia.
Origin of Hairpin Work - Materials Required - The Lace Effects that may be Produced - Threads and Silks - Some Effective Stitches
Someone of an inventive turn of mind once had a happy thought. It was to make use of an ordinary hairpin in evolving lace-like effects with a crochet-hook.
At first fine cotton was used on a straight hairpin, but the possibilities of this appliance were limited until makers of needlework accessories manufactured special hairpins, or forks, of varying sizes and materials. Then one stitch after another was tried upon these with most pleasing results.
Fine hairpin work, it was discovered, resembled lace; indeed, it once bore the name of "Maltese lace," and by combining it with ordinary crochet, very attractive articles could be made. Nowadays hairpin crochet, or fork work, has gained a lasting place in the affection of fancy workers.
Among the requisites are two or three sizes of hairpin-forks. These are made of bone, steel, or wood, with two prongs, the span of which varies from three-quarters of an inch to three and a half inches. Two useful sizes are the three-quarter inch and the one and a half inch, the former for-making small loops, the latter for loops of the size illustrated here. The hairpin-forks cost from Id. to 4d. each, according to the size and material of which they are made.
For very fine work an ordinary straight wire hairpin from a packet sold at Id. or 2d. still finds favour; and imitation tortoise-shell pins are also used. The size depends on the width of loop required, and can be determined by remembering the length of the loop is about half the span of the fork when the ordinary stitch is made.
Steel and nickel-plated forks are deservedly popular, because they do not bend unduly, and neither snap nor get worn. For cotton and macrame twine work they are most suitable. One kind has an adjustable prong, which, according as it is screwed up near the other prong or far from it, makes narrow or wide work.
For woollen shawls, and, indeed, for fleecy threads generally, a bone or wooden fork is best. One is procurable with a narrow prong and a very wide prong, which, of course, produces a narrow loop on one side of the work, and a wide one on the other.
As to the thread, ordinary crochet cotton, silko, gold or silver thread, macrame twine, crochet twist, and wools of different colours are used. In combining ordinary crochet with hairpin work, the thread for the former may be coarser than that for the latter. Naturally, steel crochet-hooks are used for cotton and twine, wood or bone for wool.
The particular merit of the hairpin-fork in crocheting is that it can produce simultaneously, or almost simultaneously, a double row of long loops such as a crochet-hook alone could not make with regularity. Moreover, the loops of one strip are easily joined to the loops of another by a method of intertwining, and they may be crocheted together in numbers of ways; while the crochet stitches down the centre of a strip can also be varied, as the illustrations in this article show.
At first a beginner may find the fork somewhat awkward to handle, but after a little practice it is usually turned about with ease.
It is best to experiment with a wide hairpin-fork and a coarse thread such as macrame twine.
A Simple Stitch
The simplest stitch attained on the hairpin-fork is worked by tying a loose loop about three-quarters of an inch in length, and leaving an end of about two inches. Now take the hairpin-fork in the left hand, prongs pointing upwards, and place the loop over the prong to the right, letting the long end of the twine lie over and be retained by the fingers of the left hand. Turn the fork half round, so that the twine encircles the left-hand prong, and in doing so change it to the right hand prong.
Take a steel crochet-hook of medium size, and pass it through the loop in the central knot, drawing the twine through it. At this point the use of the loose end of twine is apparent. By holding it firmly between the left forefinger and thumb, the central knot is kept in place. Put the hook through the left loop frontways, draw the twine
Needlework through, and again draw the twine through the two loops thus formed on the hook, as shown in Fig. I. This makes a double crochet. Turn the fork from right to left, and so that the handle of the hook is lifted over it, the twine encircling the left prong, which now becomes the right prong. Draw the twine through the stitch on the hook to secure the loop in place. Repeat the double crochet into the left loop as before.

Fig. I. "Ordinary" hairpin stitch, the simplest to work
It is, of course, necessary to work near the top of the prongs, and to push the work down the fork until it is full; the fork is then withdrawn, and the prongs are re-inserted in the last two or three loops. As the fork fills, care should be taken to avoid pressing the prongs together, as if this is done, the size of the loops will become smaller than those at the base of the fork. The twine is fastened off as in crochet, when the desired length of gimp, as it is called, has been made.
"Treble" Stitch Centre
Treble stitch produces a more substantial centre to the work (Fig. 2). The first two loops are placed on the fork, as described above, and a treble is made through the left-hand loop as follows: Pass thread over hook by turning the twine round it, put the hook through the left-hand loop on the fork, and bring the twine through. Bring thread again over hook, as shown in the photograph, and draw the twine through two of the three loops on the hook; again put the twine over the hook, and draw it through the two remaining loops on the hook.
 
Continue to: