 By 1821 he had produced a two-man machine that held , and by 1841, he had created a machine that could process up to of rubber at a time.Hancock experimented with rubber solutions and in 1825 patented a process of making artificial leather using rubber solution and a variety of fibres.His choice of solvents, coal oil and turpentine, was probably influenced by Charles Macintosh's 1823 patent.