Apparently this is also called French knitting and corking, terms which I am unfamiliar with. I can't call it anything other than spool knitting because when we were kids, my mom literally took old empty wooden thread spools and hammered nails into them for us to use.
We didn't save any of these knitting spools, as they were considered temporary pastimes like folding gum wrapper chains or playing cat's cradle with a piece of string.
Some years ago, though, my dad was cleaning house and found the doll on the left in the photo below. I believe this belonged to my sister, as I have no recollection of ever using it. Despite the fact that it was a commercial product, not homemade, it also uses finishing nails to hold the yarn.
The spool in the middle is a more recent product known as a knitting mushroom. It fits in the hand well and has large, U-shaped hooks on top which don't snag the yarn. It contains the remains of someone's old project, testament to how a well-made object adds to the pleasure of an activity.
On the right is one of the last knitting spools my husband made one year when we took down some branches. He drilled a hole through the center and added nails like my mom used to.
The yarn, and eventually, the piece of knitting, will go down through the hole in the center. To cast on, you make a series of loops around the nails. Then you bring the yarn around the outside, as seen in the last photo.
Once you have the loops on, all you will do is continue to wrap the yarn around the outside, bringing the loops up and over the yarn. Remember finger knitting? It's exactly the same principle. It's as if your fingers were curled into a circle instead of laying out flat.
Here's how it looked on another day, after we'd gotten a little farther:
Spool knitting makes ropes, belts, handles for bags, drawstrings and lassos. You can make lengths of them to add designs to your creations: snails, snakes, spirals, flowers. You can spell out your name in different colors. Many years after playing with spool knitting, I came across Elizabeth Zimmermann's I-cord and realized that it was a two-needle method of spool knitting. Funny how all these things come back around.