In 1860 Purchas and Ninnis got the country's first patent for a flax machine. It took a ton of leaves a day and produced about of fibre. A large mill at Halswell had six of their patent strippers by 1868. Johnstone Dougall (1822–1892), a carpenter, also invented a flax-stripper about 1868, which he put in his first mill at Waiuku. Dougall was an exception in declining to patent his stripper. Many others patented variations, but the basic design was that leaves were fed between rollers, then hit by iron beaters, revolving faster than the feeder, thus stripping the epidermis from the fibre. Patents included Ritchie in 1862, Gibbons and Nelson in 1870, and Williams in 1893.