James Gillingham ran an ordinary shoemaking business, the Golden Boot, in Chard, England. In 1866, he met a man who had lost an arm in a cannon mishap and had been told by doctors that there was nothing to be done about it.
Eager to put his craftsmanship to test, Gillingham offered to make the man a new arm for free.
The new leather limb he built was strong and rigid but also perfectly fitted. The medical world noticed his talent, and Gillingham soon began producing a variety of artificial limbs.
Using a secret process wherein he molded the leather to the client’s limb before hardening it, Gillingham started a business making prostheses.
By 1910, he had restored mobility and function to over 15,000 patients. [via]