WM calico printer and chemist, who invented the process of mercerizing cotton fabrics. He was born at Dean, Great Harwood, on 21 February 1791. He displayed great fertility of innovation in chemistry (especially in the discovery of dyes) and at the British Association in 1842 propounded the theory of catalytic action. A brief acquaintance with Richard Cobden influenced his liberal and reforming views. Converted in 1813, he joined the WM and applied his faith to his business and research activities. He was a reformer and belonged to the Anti-corn Law League. The firm of Fort Brothers, of which he had been a partner since 1825 ceased to trade in 1848 and left him free to experiment more widely. He was awarded a medal for inventing mercerization at the Great Exhibition of 1851. Though he returned to the Established Church in 1849, he and his family were great benefactors to their local WM church and to the townships of Great Harwood and Clayton-le-Moors. He died at Oakenshaw, Clayton-le-Moors on 30 November 1866. A clock tower was dedicated to his memory in Great Harwood in 1903 and the Mercer Memorial Chapel at Clayton-le-Moors was built in 1914.