While the Copelands have continued to perfect the old Spode china, their rivals, Mintons, have tried several new fields—tiles, majolica, pâte-sur-pâte. Herbert Minton (1793-1858)[190] and an elder brother joined their father’s firm in 1817, and, after his father and brother retired, he took Robert Boyle as a partner in these works at Stoke. Here in 1828 Herbert Minton first turned his attention towards producing tiles.[191] In 1830 Samuel Wright of Shelton patented a process for making encaustic tiles in the manner of the old Cistercian monks. The patterns were pressed in hollows into the tiles, the hollows were filled up with different coloured slip clays, and then the face was all cut level and flush. This patent was bought up by Minton and Boyle, and after great difficulties the first successful encaustic tiles were made in 1836.[192] But it was the patent of Richard Prosser of Birmingham in 1840 which gave us the tile industry of the present day. He compressed clay dust between metal dies, and made the dry dust solid under the pressure of a differential screw. The process was intended at first for making buttons, door-knobs, etc., and it was for these purposes that Minton immediately bought the patent. J. M. Blashfield, who had already had experience in making mosaic pavements, saw the value of the machine for making tiles, and developed this line so effectively that by 1842 no less than sixty-two presses were at work making white glazed dust tiles.[193] Herbert Minton took his wife’s nephew, Michael Daintry Hollins, into partnership in 1841 to look after the tile branch.[194]