Treadles harmful to your health..
The treadle sewing machine could produce "morbid effects" warned the Boston Medical and Surgical Journal in 1871.
"Two young women, sisters, who, in consequence of the prolonged use of the sewing machine, were made sick, the one with metritis, the other with a very rapid development of an ovarian tumor. In these two apparently dissimilar cases, two different diseases sprang from the same cause, which had produced in each a congested state of the inter-pelvic ovaries. It is in fact by the production of a permanent congested state of the generative system that the use of the sewing machine brings about the most injurious and most undeniable morbid effects."