I first sewed on my mum's Singer treadle, probably in the late 50's. It didn't have a round bobbin like today, it was a long thin bobbin..maybe called a shuttle? I remember her saying "whatever you do, don't let it go backwards" Guess what? Yep, it went backwards and broke something. I wasn't allowed near her sewing machine again for a few years. By then she had a more modern machine...another Singer treadle but with a normal bobbin :)