Sharpener, tool

This is a small tool sharpener consisting of a zinc roller held in a cast iron frame. It has the words 'Plesteds Patent No. 8727' cast on the back, and was patented by William Eli Plested of Aylesbury, Buckinghamshire, in 1888. It was designed for sharpening plane irons, chisels and other joinery tools after they had been ground, and required less skill and practice than the use of an oil stone.