The filename of this image, which was posted a while ago to a Ravelry group that I can’t remember the name of, is “dmcseriesv_model6a.” Some googling turned up the D.M.C. Library series, which covers all sorts of thread work from embroidery to tatting to crochet and others, most of which were published in the early 1900s. I found scanned copies of some other volumes in the series, but not this one.
I want this book, if only for this image. I think it is made of awesome.
ETA 10/6/19: Found original image & updated link to new location.