While I was there I discovered a circular sock knitting group was demonstrating how their CSMs worked. I was so interested in the process, I forgot to take pictures, but here is a link to a YouTube that shows the method.
Barbara talked to us for 20 minutes and showed us how she works a sock. It was interesting to see something that takes me a couple of months to knit, cranked out in a few minutes.
As Mom and I drove away we talked about how helpful that machine would've been during WWII, or for a mother trying to create socks for her entire family. But we both felt we knitted socks on dpns or two circulars for the joy of the process.